My son was held by his birth mother once the day after he was born. She was about to leave the hospital and she came into the nursery to say good bye to him. I stepped out and gave her privacy. That was the longest 45 minutes of my life. I convinced myself in the lobby that she was changing her mind about the adoption. The social worker eventually came to get me announcing that she wanted us to leave first to avoid the risk of seeing us outside. I never saw her again after she entered the room to hold him that last time.
I mention that back story to help put the rest of my post in perspective. I freely talk to my son about how he grew in her belly and that she chose me to be his mother. He is full of questions about her. He calls her by name saying, "That was when I was in _____ belly." (FYI I will never use her name in my blog to protect her privacy.) He talks about her like he knows and remembers her. (He did listen to her for months through the womb. He also looks just like her.)
My son is 3 on the edge of 4 years of age. His imagination is in full swing. He tells me fascinating stories all of the time. Sometimes my car is surrounded by fire and we have to summon the Rescue Bots and Ninja Turtles to save us. Other times the Power Rangers want to live in our house, eat our food and sleep in our beds. Lately, he has been working in his birth mother into the stories. She is not a super hero, but a point of reference. For example, "When I was in her belly, I did these things." "I worked at Krispy Kreme a long time ago when I was in her belly."
This recent addition may be normal adoptive kid behavior. I don't know. I am not correcting him or asking him to change the story unless he speaks negatively about her like "she gave me up". Nope, I never stand for that. He doesn't realize at this age that her choice of adoption is a sign of love not giving up.