Can my wife initiate a new suit for continued support now?

My son is 19 and taking his first semester of college in Illinois.  His mother remarried and they moved there 2010. I am active duty military currently stationed in California but Texas is my home of record. We have been divorced since 1996 and Texas has held exclusive jurisdiction over our custody/support orders up until he graduated high school may of this yr at age 19.  According to Texas, I no longer have a financial obligation to pay support for my son. My ex has just threatened to take me to court for college support.  According to Illinois law you can be ordered to pay support until your child receives his bachelors degree. Can she initiate a new suit in Illinois for continued support now? I thought there was some kind of federal law that would prevent a state to modify another states age of emancipation?  Therefore, if in your  original issuing state, the child becomes emancipated at age 18 (Or 19 if still attending high school) then that is all there is and my financial obligation has ended.