WHY do they want that? Because you went back to your maiden name? So now they can have stupid hyphenated names because you chose not to keep your married name?
I just find this selfish. If OP cared so much about the kids' wishes regarding their last name, maybe she should have kept her married name so they wouldn't all have to change theirs. Let me guess...OP can't stand her ex so didn't want his last name anymore, so now the kids get to play musical last names. My daughter can't wait to change her stupid hyphenated name at age 18.
Selfish. Non legal rant over.