I usually check the HP Lexicon for things like this - they're really good at adding stuff from interviews with Rowling, information she gives to translators, etc.

They have no first name listed for Mrs. Black.

HP Lexicon. Sitting right in my bookmark file.

*Hits head*

If I ever start writing again, I'll keep doing what I have been doing.

"I never liked Great-Aunt Black's house, even before she died."