Thrush is a tiny older lupe who lives with the Lupes of the Leaping Hart. She isn't very integrated into the pack's daily life, though; she prefers to spend her time alone in her workspace, or out gathering supplies for her medicine kit (though, lately, she's begun to drag Gideon along with her quite a bit; allegedly for protection, but I think she kind of loves him). She doesn't seem to approve of how silly and exploitative, by turns, the pack can be sometimes, but Pree has convinced her that silly, exploited lupes could really benefit from having an experienced healer around. So, Thrush remains, treating cuts and burns and sprains, taking care of the occasional birth or unplanned pregnancy, and generally avoiding half of the lupes in the territory. Gideon and Pree are her only favorites, though she doesn't mind chatting with non-dummies now and then.
Thrush has never said a word about her past, unless you want to count words like "I was born old and shriveled", or "I used to live in none of your fucking business". In fact, this is the subject that puts her into the worst of all her bad moods! Everyone learns to just not bring it up. Also, Dashing learned the hard way never to call Thrush anything like "Birdie", and everyone has been careful to pass on that information to unsuspecting newcomers.