Dear Dr. Jim,
Here's the good news: she doesn't have to close her eyes to have a successful experience with guided imagery or meditation. She can leave them open and just stare at a spot on the wall; or she can close her eyes part way, with her lids at half-mast, so to speak. This should work fine.
In fact, if she's a survivor of childhood abuse, she probably moves in and out of the altered state fairly easily, because of the dissociation she had to have slipped into during her traumatic childhood experiences. This makes her very likely to be champ at altered state techniques, such as meditation or guided imagery. She actually has an edge here.
The trick will be her learning to deploy her dissociative skills at will, consciously and deliberately. This will help her learn to be more in control of her mind states, and less likely to just slip into dissociation over the long haul.
So trying guided imagery with you is a great way for her to start doing this. If you take it a little bit at a time and move at her pace, I think she'll find it empowering. But she does need to keep her eyes at least partly open if she's to feel safe – at least at the beginning. Leave that up to her, of course.
Good luck with this and let us all know how it's coming along.