My question involves name change laws in the State of: IOWA

I have Joint Legal & Joint Physical care of my 13 & 16 yr old daughters . My 16 yr old wants to take my ex wifes maiden name. My 16 yr old has been alienated from me and there is no cooperation from the mother to joint parent. She has violated every stipulation in the decree since 2006 I should have filed contempt 27 counts. How can I stop her from the 16 yr olds name change process??