[Mixchump]

OK, here's my suggestion... Logic Pro X is free right now for 90 days.

Download it, install it on your computer.

Configure it with a routing template that allows it to receive a stereo mix from a ListenTo (recieve) plugin, with a send going to the left side of a stereo bus.

Set up an audio channel on input with the vocal mic, with a send to a reverb, and a prefader send to the right side of a stereo bus.

Set up a stereo aux that receives that stereo bus and has a ListenTo (transmit) plug in going back to you.

Get it all set up, test it, make sure it works, and then send the template session to your artist, including talking them through downloading and installing Logic Pro X and the ListenTo plugin, and then run the session from your end.

You can have them hit record on the vocal channel and just leave it rolling for the entire session as a backup...