I'm trying to do the "blood on the ice" quest and i need to gain access to 'Hjerim', unfortunately it's a master lock.

Jorleif says Tova Shattle-shield has the key, but looks as though the deaths in the family has completely ruined her, she is now just thin air and a quest marker.

I've tried talking to her and stealing from her, but no options come up, has this happened to anyone else? any help?