Her husband is dying. What words of comfort can I give her?

A close friend of mine , 77, also in poor health has a husband dying of brain cancer. She lives 45 miles from me and might as well have no children or grandchidren. They live over 1,500 miles away and seem to have washed their hands of her.
She is in an understandably terrible emotional state, calls crying loudly for five minutes. She does have a wonderful friend, a nun, who lives 15 miles from her who has taken her to mass and other places (the nun works at the hospital). I really do not want to leave my husband home alone overnight due to his being partially disabled. What can I do for her? She tends to lean heavily on her friends of which she has about five. She is on day 3 of sleeping in her husband’s hospital room and is exhausted.