I refused To Help Woman With Mulatto Kids

I was on a New York City Subway last week. A White Woman with a stroller and two kids which were obviously fathered by a Black Man.
She got off the train and needed help with the stroller going up the steps. There was no way I was going to help her. Fortunately (Or unfortunately) someone else helped her.
If I don't want to help her, I'm racist / bad person. How come the kids' father(s) don't help her? Are they bad people.
There is no way I will ever help a White Woman with Mulatto kids. I take pleasure when the Black Man dumps her. She deserves to suffer. Nobody is going to want her nor her little Pick-a-Nannies.