Mission fills out KOTOR's video-game quota for annoyingly-voiced teenage girls. Though the character has a lot of brio, it's this spunky attitude and oddly false vocal quality that makes for more than a few nerve-grating conversations as you attempt to advance her side-quest later on in the game.
When it comes to gameplay mechanics, Mission is quite deficient in terms of combat skills, excepting later on in the game, where her sneak attack can be used in conjunction with stunning Force powers to easily overpower most opponents. At the beginning, though, Mission's stats hold her back from being a real force in combat; you'll probably just want to give her a blaster rifle and hope she hits something every once in a while.
Attributes: Dexterity is the only real choice here; Mission will need the attack bonus, and the defense bonus will help supplement her light armor proficiency.
Skills: It's all about security, stealth, and demolitions. You probably won't have Mission in your party enough to really capitalize on her stealth ability, but she'll be very useful in clearing minefields and then using the recovered mines to set traps for oncoming enemies.
Feats: Like other scoundrels, Mission won't have very many feats to give out, so you'll need to pick a weapon class for her to use and stick with it. Blaster rifles are a good choice, since she'll have a hard time getting the Two-weapon fighting feats necessary to dual-wield pistols; the feats you save can be allocated to rapid shot, instead.