You might be able to get away with loading it in, straight, as a monster NPC. You'll have to have a skeleton for it, of course, but I expect you could use the default humanoid Fallout skeleton.
If you want her playable, though, it's going to be a lot of work - you'll have to separate her head and hands and hair. Link to skeleton, again.
If you just want her face - the Gamebryo engine sucks and she won't look the same.