The Labs need training, and it sounds like 24/7 supervision/rehousebreaking at this point, as MElissa has just let thing deteriorate. These dogs need care, and you are not their owner, they are not your responsibility. I know you want to help Ron, but you cannot sacrifice your own schooling and health to try to do all this, and he would not want you to. Tell Melissa if she
won't take at least the one that is "hers," you will contact Lab Rescue about a foster home for both dogs, which may be an option fopr Ron's dog while he's in the nursing home/rehab place.
Melissa sounds like she cannot see beyond the end of her own nose. As her father, Ron probably knows this about her, too, whether or not he'd say so.