I've found two bugs with her:
1) After slaying Bedlam Guy in Coral Forest I had two Vals. One had quest marker and I had to talk with her. Second one had compan marker and was following me.
2) I've overhear whole discussion with K'Tora and die after that. Had no Soul Gems, so I've revived myself at Wayshrine (that is begining of Cave). When I've reached that point again, Val started dialog for overhearing theri discussion, but there was nothing to overhear.
Sorry for not showing any screens. When I was writting that I realise how helpful they would be...