wpegg: Personally I find her the least useful, which is unfortunate because there is one short portion of the game where you have only got Flece, and have to fight some fairly tough enemies. I got through those just by using up all the potions I'd saved up (I'm a hoarder, so had tons of healing draughts and tonics).
Anyway, firstly Bow weapons, she's primarily an archer. In fact later on she can get Dark, but even when I maxed that out and set her to caster, she still just used her bow.
There's some suggestion that sneak and backstab can work, personally I found that combat is too hectic to really focus on that. Instead I threw points into Appraise (which is quite useful, and only she can do it), and lockpicking (though it took a little while to work out that you have to actively select Flece and "use" the skill before opening a locked container).
It's also worth keeping Dodge ticking along, just to keep her alive when she is in melee. Equally so do not neglect Heavy Arms, as some of her later armours require it.
By the end of the game 10 points assigned to (and I maxed them out in this order, though the lockpicking is just because I'm a completionist and hate missing things, which it turns out there isn't really anything good in locked containers):
Bow
Lockpicking
Appraise
Dodge
Heavy Arms
Dark
Thanks mate, I wondered about a bow, but, when she didn't start with one I didnt bother, shes about lv 8 now but I have been saving points where possible, I think mostly Dodge and Backstab is where I spent them.