Trys, when she isn't cracking jokes or enjoying her off-duty time in the company of gentlemen friends, does actually know her shit, and is a perfectly competent science officer -- verging on above average when she puts her mind to it. She's a bit like Reg Barclay, with different and (much, much) fewer neuroses, who was bumped from ship to ship until he ended up with a superior officer who was willing to put in the extra effort and overlook his idiosyncracies.