More info in comments

For context, my younger sister is also part of the lgbtq community, so I’m not afraid of being rejected. It’s just a matter of when and how at this point.

Give some subtle hints.
Try painting your nails a certain way or wear something different than you usually do.
If she's supportive, then it shouldn't be a problem.
Just know that nothing bad can come of this, and stay calm.

I think my mother might actually have a heart attack if I paint my nails lol

Is your mom homophobic?

While she isn’t homophobic, she is transphobic. Also she was raised in the south so I’m not likely to get away with painting my nails

Send her my way.
I'll deal with her (if you want)

While I appreciate the offer, I don’t plan to tell my mother I’m trans until I’m in college. I will try to give hints to my sister, thank you for the advice.

Alright

Well, I would say, next time you and (insert pronouns here) are alone, walk into (insert pronouns here) room and loudly say “F**K GOD FEMINISM IS COOL”

You just earned a follow my friend🤣

Or just say it abruptly, like I did. I’m not trans, I’m bi. And awkward. But yeah, people_r_us’ idea is better honestly