My mother-in-law has Alzheimer's and Dementia but she still very healthy. My husband was told she could have hospice, is this correct?

If your mother-in-law is otherwise healthy, she is likely not ready for hospice. Hospice is for people with a terminal diagnosis, generally with about six months to live. You can have her doctor clarify this, as he or she will know your mother-in-law's health situation.
Carol