Starforce

I have read 2 so far that featured Trixie. She had a very important role in both, but they were part of a series, the Perticulture Cycle. Trixie appears in the 4th and 5th stories, π and Pandelirium. Unfortunately I'd have to recommend you read the first 3 as it's a progressive series. Also it's an odd series. Takes a lot of liberties with canon.

I do remember enjoying them, though it was a year or so ago that I read em.

Really interesting premise!