Hi there! Thanks for writing in!
As you may know, Tiwa is part of the Tanoan language group and includes Sandia Pueblo and Isleta Pueblo in New Mexico and Ysleta del Sur in Texas.
The only thing I could find is a Tiwa Language Program with the Isleta Pueblo. You can check it out here. There is an email address on their page, so perhaps you can ask some questions there about connecting and finding some resources that could help.
I hope this helps!
Best of luck!