User working from home (email already in use)

I have a user who works from home and was never assigned an extension or number. She wants a number now so that she won't be giving out her personal number every time. She came in and showed me her RingCentral app and she was signed in. When I got to the admin portal I cannot not find her anywhere. I tried creating a user but it gives me the "email already in use". How can I find her account? The only way I can search is through the "Users with extensions" but she was never assigned an extension.

Thanks