Debbie, just went last week to apply for passports. There is a big sign at the post office that states, both signatures no exceptions. I did have a court document from the state of Hawaii but on there it doesn't state sole custody, so there might still be a problem with me getting my daughters passport. The post office did send everything in, so I am hoping that everythings works out. But I will let you know something Debbie.
It is so hard to get a passport for a child these days, even if you have the child 24\7 they still want signatures. I know there was another lady on here trying to get a passport for her children, she never did let us now the outcome.
Well anyways, good luck and I will let you know.
Your Florida neighbor