I think your little one sounds just great! Those milestone charts on the internet don’t mean anything, many of them are the very earliest you’d have a chance of seeing anything happen. Dagney was very expressive from the start, but I don’t remember a ton of sounds, or consistent sounds at that age. It’s so sad how quickly you forget exactly when things happen, though. My neice is about 4 1/2 months and doesn’t make a lot of noises yet. She makes some, but nothing consistent or mimicking, but she does make a lot of eye contact and reacts to people.