We are to assume that the adoption mention is a complete non-sequitur, it appears. So, we have a lady who saw her son possibly off to college, get married, maybe had kids, but for just the past ten years hasn’t come by.
That is how I am taking it. Why she mentions the adoption thing, I don’t know. She could have said he wasn’t wearing pink socks and that would have been just as relevant.
My first thought was about those FB posts where someone is looking for the child they gave up or the grown child is looking for the parent/family, so I think it makes perfect sense to mention it.