I'll see what I can do... I was already intending to use the "Explorer" module... 
That could be interesting. I had a thought that she attended Sanglamore, and partly became a mercenary because of her connections there and the potential reliability question, but I'll leave the details to you. I'm down with the Explorer module, plus feel free to use any of your custom made life blocks; it's all point-buy in the end so I'm not worried about sticking with just what's in the book as far as that goes. She grew up a merc brat and very likely learned how to pilot from her mother...hm, I should put them alongside the 12th Star Guard at some point just so Mirage can show Mama how well she's done. And done, even if it's weird that the 12SG would be fighting for the Lyrans when they're under contract to the Feds. Maybe it was a loan, it's not stated on Sarna.
So, merc brat origins, Tamar pact originally, did a short stint with the 12th before going Lostech Prospector in 3005 and has a special ability with studying star league history. Either or for Natural Aptitude or just a strong skill in it. Give her some Technician/BattleMech skill as well in there, because she's the one who comes up with the idea of mounting twin Thumpers on an Archer, and of course a smattering in Artillery, as well as art/drawing. Stick with German for language points, English as a second language of course. No Japanese yet; she'll pick that up on New Kyoto while based there.
I picked through Sarna's information year by year and came up with what Wieczorek's Archers have been up to. They're a merry bunch, and apparently like hanging out with Snord's Irregulars; they ended up first as enemies and repeatedly then on the same side very soon after. This brings them up to 3039, and builds up to regiment size. I figure they could use the immense pockets of the Lyrans to good use, and rake in some dough. As it is, they're netting 12.75 million a month in peacetime, so losses won't be difficult to replace. Time consuming, but not difficult, and expansion plans are definitely something that gets committed to. Reminder to self, post the DHS-equipped ARC-2S-LTC-A to the fan designs board.
3007: Due to its proximity to the target, Wieczorek's Archers is activated as a mercenary adjunct for the invasion of Rochelle. The invasion goes poorly, with heavy losses for both Steiner and Marik forces. The Archers return to New Kyoto to rest and refit, returning to their garrison contract once more and doing their best to fill fresh holes in their force.
3007?: New Kyoto is attacked by House Marik, unspecified units attempting to capture the planet. While the newly arrived Snord's Irregulars turned the tide of battle with their strikes against critical points held by the FWL, the Archers came through with keeping the rest of the FWL forces too occupied to reinforce against Snord's unexpected assaults. Wieczorek's Archers is the only unit to have fought against and alongside Snord's Irregulars in a single year, and soon begins a friendly rivalry with the treasure hunters.
3009: After a lengthy period of regaining their strength, the Archers are assigned to the attack on Alula Australis along with Snord's Irregulars and the 19th Lyran Guards. While Snord's forces found and destroyed the hidden fighter base that prevented their pullout, the Archers provided artillery and fire support to the 19LG during the FWL assault.
3011: With their position on the border of FWL space, the Archers are tapped for the invasion of Dieudonne. While Wieczorek's Archers deploy alongside the Arcturan Guard units, they come to the rescue of Snord's Irregulars, hitting the Jarvis Flight Militia from behind and giving the Irregulars a chance to break out of their encirclement. Whether Flade had deliberately dropped them off target was not proven, and the Archers tried to balance their loyalty to the Archon's troops with their friendship with the Irregulars.
3012: While enroute to their home of New Kyoto, the Archers end up at Callison when the world comes under attack from the FWL. While the Gryphons are considered a joke amongst the FWL, they manage to overrun defenses and take the planet. The Archers arrive as the last of the defenders are holding off the FWL assault; their mission becomes one to support an evacuation of wounded and noncombatant offworld before the surrender of the planet.
3014: Prototype testing of the Long Tom Cannon begins with several Archers' BattleMechs being selected for upgrading to the new weapon. While the installation and testing is successful, the weapon is not well received due to its massive weight and high heat. One lance remains in service among the Archers as a unit intended for breaking up concentrated enemy forces and forcing them to spread apart or suffer severe damage.
3014-15: After receiving word of the Marik Civil War, the Archers undertake a series of deep raids on FWL planets, striking at industrial centers and supply dumps underdefended by the FWL. These raids last nearly the length of the civil war, prolonged with supplies and munitions stolen from the FWL targets in the raids. These raids culminate in the invasion of Ford, which was successful and gained the planet for the Lyran Commonwealth.
3016: Beta Regiment of Wolf's Dragoons raids New Kyoto. The Archers put up a spirited defense of the RAMTech Industries laser factory in the city of Hitihito. The Archers' artillery pushed past Dragoons positions and began shelling their DropShips, forcing them to pull back and drive off the BattleMechs attacking before retreating offworld.
3019: The LCAF raids the world of Angell II in FWL space. The Archers are sent along with them with the specific target of raiding the Irian BattleMech factory, bringing along a number of unequipped MechWarriors to steal as many of the Guillotine BattleMechs at the factory as they can. While the raid doesn't seek to completely take the world, it is a success, with a number of Guillotine 'Mechs retrieved for the Commonwealth.
3020: Snord's Irregulars are lured into an assault on McAffe, with Wieczorek's Archers following after them to support the mercenaries and assist their return to the Lyran Commonwealth. A plan is worked out between Snord and Wieczorek, where his 'Mechs would pass through the sea and bypass the defense lines, while the heavy artillery support of the Archers would keep the FWL defending lines occupied and focused on a land assault that would never materialize. Once Snord's forces were in position, the defenders were caught in a pincer and surrendered, allowing both Lyran mercenaries to escape.
Late 3020: A busy year for the Archers culminates in the invasion of Alexandria, alongside the 32nd Lyran Guards, Snord's Irregulars, and Mirage's own original unit the 12th Star Guards among other mercenary forces. The invasion is a success, despite heavy losses to the Archers during the fighting. Wieczorek's Archers returns to New Kyoto to lick its wounds and regain its strength.
3021-3024: The Archers undergo a period of expansion and reorganization; they remain a combined arms force with heavy artillery support and are soley equipped with Archer-type BattleMechs. Now numbering a reinforced regiment in size, the Archers maintain two battalions of BattleMechs along with a full battalion each of tanks and infantry, and a mixed support battalion of a logistics force and an aviation company.
3024: A company of the Archers deploys alongside Snord's Irregulars to the world of Phecda to secure a water purification plant that was repeatedly targeted by the FWL. Aligning her force with Snord's, Mirage Wieczorek puts on an act that suggests her forces are joining the Irregulars in a treasure hunt rather than defend the site. When FWL forces moved to destroy the plant, she took a lesson from Cranston and hid her forces under the water at the plant, surfacing after the explosive trap was set off and dealing the deathblow to the Marik force. Only a few 'Mechs remained to retreat to their DropShip, and the Archers left the world in Snord's hands to secure it, missing out on the discovery of the hidden Colossus-class DropShip and its lostech inventory.
3027: Wieczorek's Archers take part in Operation THOR, redeploying from New Kyoto to the Kuritan border as part of the strategic rotations of troops in the exercize. They stay on Zoetermeer after the end of the exercize, while their base and dependents remain behind on New Kyoto. It is Mirage's first visit back to her homeworld in twenty years, and she reconnects with much of her parents' relatives.
3028: Operation GOTTERDAMMERUNG sees the deployment of the Archers back to the Kuritan border, participating in the Lyran invasion of the Draconis Combine. Their first target is the planet Harvest, defended by a massive force of over twenty mixed regiments, however the Lyrans apply a force of forty-three regiments in the attack. The entirety of the Archers is committed to the battle. Their next target is Mozirje, which was a vastly different situation as the world had virtually no defenders. The Archers remain on Mozirje as their experience in Japanese culture on New Kyoto helps acclimate the population to their new Lyran masters.
3030: Prototypes of Double Heat Sinks had been in production for several years, and the Archers are called upon for testing once more - this time installed on their Long Tom Cannon carrying machines, as the weapon's notorious heat burden deprived a MechWarrior of any other weapons to go with it. The ARC-2S-LTC-A model is significantly improved with ten DHS, with the weight savings allowing a battery of lasers to be installed alongside the massive cannon.
3034: The Free Rasalhague Republic is born, and the Archers return to New Kyoto after a stop at Zoetermeer and Galatea to hire on additional troops. Their return is welcomed, as the world watches the Andurien-Capellan war with worry that it will spill over FWL borders. The Archers remain on New Kyoto for several years, finally replacing losses from Operation GOTTERDAMMERUNG and training alongside other units in the LCAF.
3039: After the success of the FWL's first wave of raids, the Archers are called upon to reinforce the world of Callison, which has traded hands repeatedly in the 31st century. This was a timely transfer, as the world turned out to be a major target of the FWL's post-Andurien-war military. Timely arrivals of returning LCAF troops turned the FWL's defeat into a rout, and the Archers were moved back to New Kyoto after securing Calliston's status.