Unknown baby daddy

This girl I used to dance with is also my younger cousin's best friend. Her son just turned one and she still claims to not know who the father is. She told my cousin she tested 2 guys she was "so sure" of but neither were the dad. Her mom told my MIL's bestie that she tested 5 guys from church alone and none were the dad and none were the guys she told my cousin about. So this girl tested 7 men that may have been the father but were not. Now she's saying it was a blackout drunk night (she was 19) and it was after she did a music festival. I actually have a suspicion of who the dad is based on dates matching up and pictures of him that look like the child but he isn't one she tested and it isn't my place to say. I feel so bad that this baby is growing up without a father. On top of it all my cousin is very disappointed in her friend because she hasn't changed her ways since becoming a mother and even getting a good guy for a BF. This girl hooked up with my fiancé months before he and I started dating and so Bc he decided he didn't want her she has a hatred towards me Bc we are engaged and are having our 2nd child. Part of me wishes there was someway my fiancé was his dad Bc I have a soft spot for this baby boy and I wish I could love him like my own!! She is like never around her kid and even went out with friends on his first birthday. I see this baby at church in the nursery with my son who is 3 months older than him and I just want to hug him!! He is always wanting me to pick him up but I can't and laughs when I talk to him. The girl's mother is basically raising this sweet boy and she is so wonderful to him. But I have a secret wish that he and my son will grow up and be best friends so I can be like his "other mom" you know how your bffs parents can be like your own lol I know this is so weird but if you saw his sweet chunky smile you would have your heart stolen by him too!!