I also knew her for only "that one BT book" - incidentially, the first BT book I ever read. Took me all of... 3 hours I think to read it back to back, and I was hooked and grabbed the next BT book (Thunder Rift) that day.
For all those who haven't read it, there's a detailed plot synopsis over at Sarna.net: The Sword and the Dagger
The article also covers her brief essay about "Writing BattleTech: The Sword and the Dagger". From what she said there, it seems the book was written under a special contract different from all other BT book authors and that contract is the reason why FASA (or FanPro, or now Topps/IMR/CGL) could never re-publish it in English.
Rest in Peace, Ardath Mayhar.Edit:
Lysenko, where did you get that picture from?