I'm in a similar situation with my mother-in-law. I'd happily pay a bit more each month to support her Netflix account. If they block her, we may just cancel the subscription completely.
My mother-in-law is a self-proclaimed useless person at anything technical. You don't know how many hours it took for us to explain her phone to her. I gave her a Netflix profile and signed her in to my account. It makes life so much easier. I'd happily pay more for the ability to share my account with her. At this rate we'll have to administer two accounts from our house, rather than let her use mine. Why are they just making this harder, rather than just asking us to pay more to continue doing what we're doing?