Is it legal for an attorney to have me sign a paper without having it notarized?

My daughter went to her fathers for the summer and he never returned her. His attorney sent me a paper for a new custody agreement sayong her father has custody of her now and I am to see her for holiday vacations. Her father called and told me that his attorney said he doesn't have to bring her down because he works but the new agreement says he is responsible for transportation to and from. However the paper I signed was never notarized and no witness was around when I signed it. I called the court house and the last thing on file is the judge saying the girls are to remain with me. Amd go to their fathers every other weekend. I have not seen my 13 year old since June 25th, 2018 when he picked both girls up. What can I do to get my daughter back.