Legal Question in Family Law in California

Absolutely. What she has done is totally illegal and prossibly criminal. The first thing to do is call the police and give them the details. Since you are non-custodial this may be a purely civil matter, but it is possible they will treat it as a parent abduction. Next you need to hire an attorney. This is not going to be a simple, do it yourself case. You will need orders issued from the California courts for them to return to California and for the mother to face contempt charges. Then you will need to have those orders enforced in Texas. This is, unfortunately, a common enough thing that the courts and authorities are used to dealing with it and know what to do to get your daughter back once you follow the proper procedures and channels. You will, however, need an attorney to make sure you do, in fact, follow proper procedures and channels.