nope. later on it gets even destroyed. You can always give her another two hand weapon. Its just, for a long time, her weapon is quite good. Later on, you will have better ones available.
Figures means you have to plan on that from the start. and the game calls it a Bastard sword so if you weapon focus it that gives you two BS weilders and I doubt there are many great blades in that track.
Yes. an experience, you make during midgame. If i would start again, i would concentrate on some other weapon from the start. two hand swords or two hand axes.
But i don´t know completly. the game crashed before i could finish this quest. I cannot contiune until some patch takes care of that. Could be, that after this quest you find another good one. But as i said, there are really good two hand swords or axes around, which can be better then her sword.