Hey Ariel. Thanks for reaching out.
To give you an example, I didn't realize I was not a cis female until I was 29. I started hormones at 30, and have now been on them for nine months. The changes I experience are exciting, and I feel more like "me" because of them. Gender exploration, for me, has been such an enlightening, open, and thrilling process. I fully support anyone questioning their gender, whether they're 7 or 70. It's a very personal journey and it's completely unique to you.
I do want to note that your choice in hobbies and dress don't necessarily mean you're not a girl. I don't mean that in a dismissive or invalidating way; it's just certain activities get labeled from a very young age as "masculine" or "feminine." It's hard to base gender on that alone. But in the end, you know you best. I know that's hard, when you're looking for answers, or to simplify things, but it's the truth. If you say they/them feels right and you're outside the binary then that is perfectly okay. It may change, too, and if and when it does that's okay, too. This is not a straightforward process, and it's okay to change and experiment.
I hope this helped. Feel free to
PM me if you need anything.