can it accept calls from external? can it make outgoing calls? 

Check if there are any blocked numbers in the admin portal > Users > Click on the user > Phone > Blocked numbers

No, there aren’t.  She can make outgoing and receive incoming calls.  I just can’t call her extension.  When I do, it dumps me back into my voice mail.

When you say “dumps me back into my voice mail” do you mean that you can leave a voicemail to your own extension? Or do you mean you are dumped into a menu where you can check the voicemails other peoples have left to you. Either of these sound impossible tbh, so I think your best bet is to contact support and show them a few example calls they can look into. Something like example below:

Call1
From: 
To:
Date:
Time:
What happened: I got dumped back into my own voice mail