You have very good intentions, but I would find something like this very awkward. It's possible he would be thrilled by something like this, but I do not think you should do something like this unless you knew for sure that he would appreciate it.

Describing what you see to blind people is like showing what you hear to deaf people, they never heard any of it, he can’t even make is idea of what long brown hairs look like u know, that’s how I think about it maybe I’m wrong tho shouldnt have answered

I can't speak for all blind people, but an adapted photo might not be the way to go, it might be different for people who lost their vision but I don't yearn for photo's of anyone. But you could write him a nice long email, like it was a letter.

There's a lot of software and hardwire to make tactile graphics but a family picture would likely be too 'busy' tactilely. Tactile graphic production material is also very expensive- my team and I write grants to be able to purchase it.

You could create a word document that could be sent to his braille device, if he's an electronic braille note taker user. The word document could include detailed descriptions of family.members a little bio for everyone. Just don't PDF it- it'll be useless.

The problem with making braille is you either need an embossed to 'print' braille or know how to use a slate and stylus (long sentences aren't fun). It would totally be doable to learn the basics of slate and stylus and write your name and a little greeting, like "hi I'm Name, and I'm your cousin!".
If you're near an agency or non profit that supports people who are blind and/or DeafBlind, they may be willing to create a short card in braille for you. I get asked to make those from time to time.

A long while back my mom made me a photo album and we were going to do digitally recorded audio captions but then that idea fell through so now what I want is for me to write up Braille descriptions of who was in each picture and where each picture is, just too bad the pictures don't come out of the camera with dates attached if you know what I mean, because that would make my descriptions more complete.

I bet some one over on the 3d printing subreddits could help you out with this. There are a few etsy shops that do lithophane its probably not perfect but it is something with depth and texture. Good luck