All new to me and so many issues

Hello, I am trying to set up Team Viewer on my laptop (Mac), and my mother's laptop (Windows). She is 93 years old and needs constant help with her computer. I have set up an account on each computer. Mine seems to be working fine, and I have added her as a contact. But, when I try to connect with her (I know she is on line because for the moment her computer is right next to mine), I receive a message that the contact is not accepting incoming connections.

Second, her Team Viewer interface looks different than mine, and I can get her computer to remotely access mine, but not the reverse. She is never going to need to remotely access my computer, but I need to remotely access hers! Please help.