It's Zoom we are trying to sort out!
You can't do account elevation in Zoom for any task that needs aministrative privileges. I don't think there are any cheap/free/easy options that actually work.
I would, for close relatives, install a Firewall at their location and put a VPN server on it and then enable Remote Desktop on their PC. You can then use Remote Desktop Shadowing. There's a disadvantages here in investing time/money up front, requiring Windows 10 Pro and also requiring a Windows PC at home.
If you can spare £40 a month (annual subscription) there is GoToAssist. If it's a one off, a monthly subscription is £50. Spendy but it works - you can put a session in `Admin Mode` if you have administrator credentials and then you will be able to see the User Account Control dialog when it is displayed and any windows which are elevated.