I got full custody of my first two daughters, and because Alabama's court system is still dragging its knuckles in the stone ages, the courts would never support me in forcing her to pay child support. So, I just dropped it. But, it has some of the strictest deadbeat dad laws in the US, but it doesn't apply the other way around.
I just found out recently that I had a 14 year old daughter that I knew nothing about. We did the DNA thing and it came up BINGO. A one time thing... And, because Alabama has the worst laws in the state, when her mother went on disability, they tracked me down, although the mother never wanted me to know. And, because she had no income because of disability, I had to pay for back child support. She is 17 now. Her mother flip flops on whether she wants me to pay. One day, she is begging me for a few dollars, then when I give it to her, she tears up the check and tells me she doesn't want the money. I have a feeling it will be a roller coaster for the next few years. I have her on the phone and texts cussing me for paying her, so at least there is that. It's so damned weird.