Hi Nancy, there is no way that any other board settings can stop anyone using this board - it's just not possible. Smiley
I suspect what she is seeing is that the login box is being filled in by her browser (it's one of those helpful things that browsers do) and so she is assuming this board is recognising her. What is probably happening is that the browser is remembering that she has used that login/email address in a login field that looks (is constructed) the same as the one here but of course the database (which effectively operates the board) has no record of her so will not allow her in.
The GMB will not allow two registrations from the same email address though, so if she has tried to register and not succeeded I'll probably find her stuck in the pending list. Can you ask your friend to email me directly with the details she's tried to register with here and I'll check it out and get her sorted. My email address is behind the envelope icon to the left of this post if you don't already have it.