Asking that a guest be accompanied by a nurse?

Megan+Adam

I have a very elderly great aunt who has very significant mental and physical impairments. She generally doesn't know where she is and the left half of her body is paralyzed from a stroke. She also needs to wear a diaper. 

My grandmother, who is not physically capable of attending to her sister's needs, tends to bring her places and then enlist other family members to do thing like changer her diapers and lift her. In addition to making people uncomfortable, I feel that this is an accident waiting to happen.

I am more than happy to have my great aunt at my wedding, but I really want her to be accompanied by someone who can provide adequate care for her. Also it isn't really fair to put my other guests in a position where they'll be asked to change adult diapers at the reception. 

Can I say that my aunt is invited, but she has to be accompanied by a nurse? Or should I just not invite her?