I don’t have personal experience, but have enjoyed reading this trip report that kind of does what you’re talking about.
What time does your mom normally get up? Mine is a new guy owl, so getting up early wouldn’t work. I’d probably plan on having her guys be me a call when she was ready to go. I guess what I’m saying is that like trying to stay within the schedule of small children (let them nap when they’d normally nap), that would probably be the best way to handle things with your mom.