First question, from the way the media is reporting the story yes it is allowed and in fact that is precisly what took place as she entred the facility
Regarding your second question: Then (i assume) they would do cpr and if not the nurse wouldve been wron for not helping somebody who never agreed to forgo cpr. My understanding is that when entering the facility the resident /family agreed that the staff would not perform cpr (havent we been through this point?). (Again, though I agree she shouldve found somebody who would do it.)