Family Tech Support: Remote Support/Training/Control/?

I'm a non-Mac user who just agreed to take on support for my Mac-using 75 year old mother.   Looking for any suggestions for *free* remote troubleshooting/remote control?   - Rustdesk viable/good? Other FOSS viable?  - GotoMeeting/GoToAssist? Other non-FOSS with really free home use? - Something in-house that I'm missing? Note: not just looking for screen-sharing. Want to be able to control her keyboard and mouse, demo program usage, resolve issues, etc.