Hello! I've looked into your project and I'm pretty impressed! I'm a full time pixel artist, but I'm honestly not the best at ASL. If you would like some environment art or any other animation work please reach out to me on discord: Rojatzo.
I would also be completely open to learn ASL fully in order to help you in your game. It couldn't hurt to add one more language to my knowledge.
Edit: I forgot to link my portfolio, so here it is: https://rojatzoart.com/