How to set up silent FaceTime calls on iPhone XR?

Trying to set up a call or FaceTime so I can monitor my mom sleeping so when she wakes up and is ready to get up I can stop what I’m doing and assist her.

the issue is I don’t want to have the iPhone Xr lighting up or making a sound that would distract her or disrupt her sleep/resting time which varies.

[Re-Titled by Moderator]