Well you're off to an amazing start. Reaching out and trying to understand is the best thing you can do. And it's true. Anyone can be here was long as they're not making anyone feel victimized.
Your child is extremely lucky. It's a tough world to be in sometimes but with a healthy home life it isn't as scary. A soft place to land after the hard world had as go at you I'd truly the best thing they could ask for.

"They" used to act the same as "You" in that it could be both plural and singular. It wasn't until later that people decided it shouldn't be used singularly. If you're not sure how to use it, reference "you". Use (and supply) context to determine plurality, "are" instead of "is". I personally use "themself" as we distinguish between "yourself" and "yourselves", but there's mixed information about that. Either way, "they" is an appropriate and viable third person singular pronoun that doesn't indicate or misgender with a binary gender.

As far as I am concerned, if you are not a racist, bigoted, misogynist and have an open mind and heart - then hells yes, you are welcome here.

But that's just me - I'll be over there if you need me.

I'm cis-male and have been welcomed here, no kids...just supportive.

I'm sure you'll be very welcomed and maybe others here can give you good info or just being supportive is also necessary.