To be honest, I am not sure. I believe apps will stick around if you switch accounts on the device, you just have to make sure the new account "owns" a license to those apps to continue using (or updating) them.

A few years ago my MIL was looking for a new phone and was asking for recommendations as she was moving from a simple flip phone. Everyone in her family was suggesting Android, as that was what everyone uses. I off-handidly suggested an iPhone might be nice because it was easier to setup and use overall (not as much configuring as Android, though I like both OSes), so she ended up getting an iPhone. Overall, I think she was fine with it, but I found the biggest issue was setting up her services like iCloud and email, etc. I will say that she has trouble with buttonless phones, though, so the SE would be my suggestion. Either way, help with the setup and all of the apps/configuration if you can.