I know this post is old-ish but I was wondering the same thing. Do anybody here now about this Wing Ma'am app? At first glance, it looks like a good solution for lesbians having trouble finding other lesbians.
Well, after not getting a response here I just downloaded it and tried it out... It doesn't show me any events... Maybe there simply are no events near me, no idea... It doesn't show a lot of people... But I'm from Germany and I think it might be less used here considering it's an american (?) App... It is free though, so you could just download it and check it out yourself