Our yorkie,Willy,was 4yrs old when we adopted our daughter. I was a little concerned how he would react to having a 1yr old around, but we have had NO problems. I know when we finally got home with her(we were away 17 days)he was so glad to see us that he couldn't kiss her or me enough, and I dont think he cared who we brought home as long as we were home.
We only had one time I was concerned about them, Mandi was around 18mo and I came into the living room to find her, and she one hand around Willy's muzzle, the other hand on the other side of his muzzle with a nice big handful of hair, and she yanked him towards her to kiss him on the nose. My heart sank as I said , Willy be nice! Mandi be nice! He could have really hurt her, but chose not to.
Willy really loves his little girl...