@empathdad, that's very cool stuff. I like to think one of my favorite grandmother's had been visiting my daughter, but I have no idea. I also had an extra special grandfather that had passed. But it's hard to say who it was. That's cool that you got confirmation. And it is not uncommon for deceased relatives to pop in and visit. When children are babies they are still pretty connected to the spirit world/heaven where they came from.
@spiritualskies, this is kind of off topic. But something you said made me want to comment on this. There are definitely entities that can mimic your loved ones. I've read many books and articles where people stated that demons often show themselves as a ghost child to trick you. I personally have had about 5 spirits in my home call my name using the voice of people who I know. And they weren't imitating deceased people I know, they were imitating my son, wife, and Dad calling my name from across the house when I was the only one home. It scared the crap out of me. I also had on another occasion when I was alone at home heard a woman humming a song in the kitchen. My dogs were nearby and were all bent out of shape with hair up on end. I went in the kitchen to investigate and the singing stopped although I could smell perfume.
It's a little frustrating to me since I rarely see ghosts but have a very keen clairaudient ability. So I hear things but can't really investigate since I can't see things. Anyway, I wanted to share a little of this with you eventhough it's a little off topic.
The theory that I have heard from many respected psychics is that when we are born our spirit accepts a mission or life quest. Before coming here through birth we pick a support group that includes many spirit guides. And often times those spirit guides are relatives or very close friends from a prior life. And after birth and early on as a baby, we are still very connected to the other side and can see and converse with our spirit guide support group and our close friends and relatives who stop by to visit. But as kids get to speaking age they lose most of that connection to heaven and forget the mission. At that moment it's supposed to be a free will experiment where the mission assignment is forgotten and the baby grows up and makes free will choices to try to be who they were meant to be. Some people grow up and nail it and check all of the boxes of their life assignment. While others never come close to realizing their assignment. It's very fascinating. In any event, if a baby is talking happily to an empty room, it is very likely that they are communicating with their favorite relatives and support group from the other side. If the energy feels good to you and your baby is happy during those talks with the unseen, I wouldn't worry about it being anything negative.
And sorry that I got a little wordy-again!
P.S.- There is a really cool tv show that used to be on about kids who passed through baby-hood and still remembered their past life and relatives and friends from the other side. This is very rare since again once babies can talk those memories of past life and their current life assignment are usually intentionally lost. I'm not sure where you can watch episodes, but the stories will blow you away. https://www.imdb.com/title/tt3107588/