Well, I'm not sure about that - a large part of Fluttershy Leans In contradicts that idea directly IMHO, or at least puts a damper on it as her main income source. Perhaps she does that sort of thing on commission (as with the early ep of Rarity asking her for help with Opalescence), but as an organized source? I doubt it.
Before we saw her brother , I thought that she had some access to a trust fund or was doing the equivalent of living off interest - she has a modest lifestyle, but doesn't appear to DO anything for income unlike the other ponies, and does things like organize fundraisers so she has a fair bit of free time on her hands. Unfortunately her brother's lifestyle, bouncing from job to job and then going back to live with their parents, probably means that isn't true. Maybe an inheritance from a grandparent that he squandered but she invested in a little self-sufficient cottage? Perhaps she's a landlord for some Ponyville resident which is her only real income?
What I find crazy about all that speculation is this: It doesn't feel out of place. A lot of shows stop holding up when you speculate about them like this, even regular shows - I read an article talking about how fictional New York apartments stack up cost-wise versus real New York apartments, and it was funny just how out of whack some of them were even if I've never been to NY. Friendship is Magic, though? It feels like they've thought about this too, at least somewhat.
Applejack... I dunno. She does have the only episode that has actually pissed me off - The Super Speedy Cider Squeezy 3000 - but her main growth episodes have been centered around learning to rely on other ponies, not just herself. It never really bothered me the way it repeated the lesson, because each time it was done in a different way and AJ seems like a VERY stubborn pony who doesn't learn very well. "Well, golly, I did learn to rely on my friends, but relyin' on my little sister to stay out of trouble?"
What's her line out of SSCS3k? "I didn't larn nuthin'!"
