Just because your dog is friendly, it doesn’t mean they will joyfully welcome your new baby. I work with a lot of people who bring home a new baby and discover their dog is very unhappy with the new addition.
From the dog’s perspective, this is a big change in their routine. There’s often a change in exercise habits, less on-demand attention and usually an invasion of their space in a very different way. These changes may last the rest of the dog’s life and, as children mature, things continue to change over several years. That’s a very big adjustment for the family dog.