Ladies Rock Camp: Winter Edition
"Any woman age 19+ can sign up for Ladies Rock Camp. NO MUSICAL EXPERIENCE NECESSARY / ALL SKILL LEVELS WELCOME. You don’t have to bring your own instrument, but feel free to do so if you like. Willie Mae Rock Camp for Girls welcomes campers who identify as female, trans, and gender non-conforming."
It's not free, though, so best bet is to sign up with a friend or two to get a discount.