Screen share begins immediately, with no option to select a certain window or share sound

Hello, 

I was trying to show someone I supervise how to share sound without sharing screen (go to advanced options inside the share screen pop-up and select computer audio). But when she clicks Share Screen, there is no pop-up! Zoom just begins sharing her screen immediately. She has the most updated Zoom version. I know she has a Mac laptop, but I don't have more info about it. I have googled this to death, but not found anyone talking about the same issue. 

Thanks in advance for any guesses about this!

- Holly