We had a pixie in one of our games. He ended up quitting because he was SOOO underpowered. +4 LA is a LOT. The dex bonus just exactly cancels that out for dex based skills, but you lose feats and hit dice for it as well... The dex makes up for the loss of levels for hitting, but you're still
Sure, at levels 12+ you start to become halfway decent, assuming you're playing a rogue or some very very similar class. They are abysmal fighters and spellcasters because of the LA. Rogue is your only choice.
As others have said, the arrows are not a feature of the race, so she doesn't get them.
I think you'll find it's fine... but I really hope the player is an experienced player, because an inexperienced one will get herself killed in the first battle.
So... I think they're fine. In a normal, fairly battle heavy campaign it'll be good, slightly underpowered and horribly fragile. In a stealth based campaign they'll be really good.
*shrug* No huge brokenness here.
-Nate