What’s with the different family name of the mother and her son? Is it a personal identity choice or something else?
Could be she was married at the time, and that’s her ex’s last name... or she was single at the time, and that’s her maiden name.
When my mom and step-dad married, I had a different last name -— until he adopted me and then I got the same last name. That was almost 50 years ago now, though.