what's her worst case scenario; he develops dementia, alzheimer's, etc. and she has to take care of him. does she love/care for him enough to put his well-being and care BEFORE hers?
isn't that what true love is, to willingly sacrific oneself for the loved one? and if he becomes 'ill' soon wouldn't she want the best care for him?
she has one question to ask "how much do I care for/about this man" can I give up living an active lifestyle?"
there is a possibility that she will become 'ill' BEFORE him. and she will have him to take care of her.