I adopted a little girl who came to the door. She was 3. I had a two year old already.
Today when I opened the game they were both 4. One aged and one did not.

They had different birthdays.

stonzee, you probably have already noticed that your adoptee turned five before the one that was 2 when she was adopted. I've had that happen. When that happens your 2 yr old was more like 2 and a half or more when the three year old was adopted. Big hugs!