How do you tell your friends that your mum is a lesbian?

You mean ' How do you tell your friends are mad if you tell them you're a lesbian'?? That's easy, they avoid you and make fun of you publicly. It also means you need to get new friends. If you mean...

Well the way I see it you can slip it in randomly in a conversation, Make it fairly obivous so that it isn't a shock. Or sit them down at once or seperately and tell them.

You could look for signs as if she gives you [if you're a girl] or another girl flirty looks, acts indifferent around boys, laughs or twirls her hair while talking to girls ect.

Well first of all, don't be afraid, This is a common thing with women/young ladies now-a-days. If you have these feelings for your friend, basically, make your move, let her know your passion and...

Ask her