involving the other side's family

My boyfriend ran away when I got pregnant, now I'm 37 weeks and I'm getting into the dilema if i should tell his family about the baby, considering that we know each other since we were kids, I don't want to pick up a fight I just think Granma has the right to know about my son and from my side if she wants to be a part of my son's life she is more than welcome but I don't know if it is actually a good idea, please let me know what you think