Scheduling blocking of outgoing calls for adult with dementia

I take care of an eldery person who lives for their iphone. The problem is dementia can mess with one's perception of time as well as their short term memory. She's calling folks 20-25 times in a row after 11 pm. It's not cool. If she was aware of her actions, she'd be mortified. Is there a way to block specific numbers during specific times?

She is on her own account. If I had her join my "Family" would there be any cross contamination with payments, etc?

I know there must be a way but I can't fumble around with it while she's sitting there; I have to know what I'm doing when I go in.