This makes NO SENSE in Maine

Question -
Can a parent (mother) who was basically absent from the first 2 1/2 years of a child's life sue the father (who had him for those 2 1/2 years) for back child support even though she never had the child with her except for maybe 1 day a week at the most? There was (and is) nothing on paper about support or custody...

With the information you give, No.

But he need to get something on paper, and quick if she is thinking about court.

This was something a lawyer told him. That just made no sense to me. He's going to ask her (the mother) to go to a mediator with him in a week. The plan is to get his parental rights on paper, as well as the child support guidelines established. He hopes she'll go and not make this a huge issue - no one wants to go to court and he certainly doesn't want his child to go through that. Thanks...