flees w/kids to another state

My daughter has left texas with her 3 kids and came to stay with me in california.Her husband told her he wants a divorce and that he has found someone new.She agrees to this,but he says he does not want to pay the child support payments his lawyer tells him he will need to pay and threatens to take the kids or kill all 4 of them.My daughter gets scared and comes to me. Now she has no way of supporting her children and her husband has taken all her legal papers and belongings,so she can not enter the kids into school.
How can she get child support here in Ca,? Her husbands is telling her she has kidnapped her children,although nobody has yet filed for a divorce. He refuses to help her financially. Is what she has done illegal? I told her it is not illegal, but she needs to hear it from a professional. And what are her rights?
Please help, as we are out of funds and need to get the kids in school. Thanks from a worried Grandma