I did let my daughter decide not to have anything to do with her father. She is 13.
From age 4 to 10, he only showed up twice a year. And sometimes those visits were only initiated by his mother. He felt our daughter got in the way of his dating. She was a "****" block as he referred to it as.
I moved closer, he popped back in playing "daddy." Now for the last year he is again dating another woman who doesn't like kids. From July of 06 to Dec of 06, he saw her 4 times, briefly. And I'm talking only for a hour to a couple hours at a time. The last time he has visited, called, emailed, or anything was xmas. It's now August 2007. My daughter has full access to email him, knows his phone number, and she has came home to our house destroyed by him. He didn't even acknowledge her birthday.
She has made it clear she wants nothing to do with him or his family. And I just tell her that his her decision.
So yes, sometimes a 13 year does know what they want.
Legally, you are an idiot.