I been best friends with her since Febuary and barely knew her before then except she liked to make pokemon sprites last year. Anyways, last time we hung out, I joked around about being gay and she said she wouldn't mind if I was. The only problem is I am bi and her mom and my mom are close. Should I come out to her?
If she's okay with it, sure! I assume you're worried that your best friend with tell her mom who will tell your mom? Because you could always tell her, then ask her to not tell anyone else until you're more comfortable. Go for it, and good luck! x
Tell her, but make sure to specifically mention that you are worried about her mother telling yours before you are ready. I'm sure she will keep your secret for you.