MRSA could be very contagious for that patient. MRSA is a contact disease but being that the immune system is low they are more apt to get it. Also if she has a cut or wound because it allows the virus to get in.
I recently underwent partial breast radiation (breast) and have contracted MRSA. They are treating me with Cipro. I am on my third week of it now. Apparently I acquired it through the catheters in place during radiation.