Can I take custody of my son from her?

Ok, I share joint custody with my baby's mother. The child is 4 years old going to be 5 soon in february. We live in texas. The mother has ventured across the globe to kuwait and married some kuwaity citizen and has converted to islam: the works. She plans to reside there in the near future and has told me she is going to give my son to me. However, she has already left and no papers have been signed. My son is here with me and I am still paying child support. Can I take care of this without her since she has essentially abandoned him? Can I go to some office?