You can use Zoho Assist to remotely view your mothers iPad. But as far as I know. Remote control is not possible with any service. As Apple doesn't allow that.
Install the Zoho Assist app from the App Store. Then you can access for free via Spiceworks free remote support. It'll generate a session ID you have to tell your mother to put into the app for each support session. So, it's not going to be like a computer. Where you can simply login whenever you want.
Connect and control other computers across the Internet, by sending users a quick URL. Unlimited sessions, technicians, and workstations, all for free!
community.spiceworks.com
iPadOS, iOS, TVOS and MacOS also have built in Switch Control. Which as I understand allows limited remote control as well. The catch is this only works between Apple devices on the same network. It won't work outside...