I feel the urge to help

So yesterday i was in the e.r. because i had strep throat and on my way back home i was waiting for the bus. There was this young (17 or 18 maybe) asian girl pushing a stroller, and two of her friends. I wasn't trying to listen in on their convo but it was just so familiar. She was talking about how the BD was all for the baby when she first got pregnant but towards the end he became an loser. He said that he wanted so see other people and took a friend of hers to the movies when she was miserable and in pain. I just wanted to reach out to her because everyone needs support. I just didn't know how to approach. I have two kids with two different fathers and they are both deadbeats. I told them i do not accept half steppin. You either get into their lives completely or go away and pay. No dad at all is better than a half ass dad. I didn't know what to say to the girl. How do you approach someone you want to help with crossing the line into offensive nosy person who can't mind their business???