I think it is so sad
that at this time in her life when she needs her "best friend" more than ever, that your granddaughter is denied him due to a landlord who doesn't allow pets. There are laws in place now to protect people like your granddaughter and that understand the important role a dog can play in a person's life.
I am sure that Murphy would qualify as an emotional support service dog under these circumstances and the apartment would be obligated under the law to allow him. She just needs a letter from her counselor saying that the dog offers her emotional support during this difficult time and will help her during her parent's divorce. It is that simple. If you need assistance with this, I would be glad to help. Here is an internet article about it.
http://www.bazelon.org/issues/housin...nfosheet6.html