At least you can give some social login choices to lower the entry barrier.
This discussions aren't public and given the target the value proposition is discussions without personal bias(anonymity until the end of the discussion).
And social logins are next in the bucket list :)
So yes, she'll know it only in the end. Also for the other people, contributions are made and discussed without having to think about who wrote it but what was written and how much of a good contribution it was(through likes, also visible in the end).
It's a way to skip that part of biased reasoning that could come out and shape the answer when someone knows that he/she is answering its boss/manager/coworker.
Do you happen to know about this possibility?