Interesting question. My word choice is 'at a disadvantage.' I know women that are single moms, never been married, no longer together with the father. I'm noticing that my category is a slight differential. I'm a divorced single mom. I think that I've noticed there's a twist to this when I moved back to where I finished high school and lived with my mom and stepdad until I finished college. The big question asked during their pediatric appointments is, "do they see their dad, regularly." I believe that's an important question that touches upon this thread. Around me, there's plenty of nuclear family dynamics. There are some young moms as well, but I've noticed of them, strong immediate family support.
Your mom's immediate family seems to have played a role in this, I'm guessing? I'm guessing, also, that I have it better than 50 years ago. I'd probably have been married off after divorce to a man of my family's meddling.