Hard to answer definitively on these facts. Need more information, such as where the process is at, when you moved to Illinois, where and for how long the children have lived in Illinois or elsewhere, etc.
It also sounds as if you've already consented to jurisdiction in Texas and waived your objections to jurisdication if you've hired an attorney and have appeared in court there. Ultimately, if you already have an attorney representing you, other attorneys are prohibited by our ethical rules from counseling you substantively on your case knowing that you are represented. Illinois Rules of Professional Conduct 4.2.