Somebody gave me this idea and it really helped at night. Put down a plastic mattress cover, a sheet, another mattress cover, and another sheet. That way if she has an accident you can just quickly take off the top sheet and mattress cover, clean her up and both of you get back in bed.
I hope you don't mind, but my recommendations from pee smell come from having so many dogs and fostering dogs. Recently, I've heard wonderful things about fabuloso. A friend's tiled house smelled like pee badly when she was house training her puppy. She said Fabuloso is the only thing that worked. We're moving into an all tiled house and I plan on picking some up between 4 dogs and 2 kids! So you might be able to use this in the bathroom. It's an all purpose cleaner. If it somehow got in carpet, putting oxyclean in your steam cleaner really does the trick. I fostered a lot of puppies and people were surprised my house didn't smell like dogs. As far as a mattress, I'm just not sure how to go about cleaning that. If you can steam clean them, maybe try it with oxyclean too. I just don't know to clean a mattress. Also, use the oxyclean in your washer on the items she peed on. That will help. I've also heard of people spraying areas with vinegar.
I hope this helps.
L.