In college I got a girl pregnant. She was distraught, embarrassed, upset, angry. While dealing with her feelings I found out I had another girl pregnant. I put them together with instructions to figure it out. Having sibling babies changed everything, they concluded on getting married. I flipped a coin, heads won, and that's the mother I married.
They teamed up and cross baby sat, graduating in December instead of a June graduation. When we left college they had sworn unity, never breaking their kids up. We moved for work, and set up house in a rental. They wanted age proximity and had their second babies.
Today is a long time later, we stayed put for the sake of the children, bought one house and moved once into our current house. They are more than best friends, they are both mothers. In thirty years I never heard them argue. They discovered cruising after the kids moved out, and are strict grandmothers.
My life, I can't compare to a singleton mother. I would never trade my luck for another.