Not Sure What Steps To Take For Minor Child.

I (30f) share a child with my wife, however, I am the only person who has legal custody of my daughter. Short back story, I had her in Florida(we have lived in Indiana for 5 years), biological father didn’t sign her birth certificate, as he broke up with me the day we found out I was pregnant and refused to come to her birth or nicu. He’s met daughter(8) ONCE, and other than that outside of his occasionally popping up to leave again, he does nothing. No child support, phone calls, texts. If I don’t reach out to him, he doesn’t speak to me(longest stretch 3 years).

Now the complicated part- I’m dying. And not like, oh haha let’s be dramatic. I’m dying a slow burn death. Obviously, my goal is to make it until at least my daughter is 18, but I can’t bank on that.

My wife has been there, every single day, for our daughter. Her father has been there for one single day? My biggest fear is that I die early and the courts seek out my child’s father instead of her mom, who knows her and loves her.

I can’t currently afford a lawyer, so I thought I’d ask here. Is there anything we can do? The father’s parental rights haven’t been terminated, although without signing the birth certificate or establishing paternity I’m not sure if he even has rights like that per se?

TLDR: dying bio mom, pos bio father, step mom willing to step up all the way but need advice on how to go about it.