In the first Palace War, Original Quest #17, Cutter and Skywise discover Picknose and Old Maggotty working as mine slaves for Guttlekraw:
http://www.elfquest.com/comic_viewer.php?fd=/gallery/OnlineComics/OQ/OQ17/_Original ElfQuest - 17_page=1#_24#
In this whole issue, I didn't notice any other women or elderly Trolls working in the mining pits. Guttlekraw kept women in the women's quarters. Why was Maggotty sent to the mines?
Picknose, Maggotty and Oddbit were captured long after the rest of their people, so they may have been regarded differently by their captors. I can see why Picknose would have been sent to the mines. He was ambitious, a potential troublemaker, so he would not have made a suitable guard. Oddbit became the king's favorite, which has been her roll with three different kings. But in every other life situation, Maggotty has been valued for her medicinal skills. Certainly she would have been valuable as a medic, to Guttlekraw's army.
Maggotty was probably satisfied that her granddaughter Oddbit was at the king's feet, instead of in the mines. Perhaps she made some kind of trade-off to help Oddbit secure her own comfort and safety. Maggotty seems too smart to have made enemies with Guttlekraw. Guttlekraw seems to be too resourceful to waste Maggotty's skills in the mines.