These lyrics sum up the relationship between Aidan and Eva at this point better than I could ever do it on my own:
When you're the best of friends
Having so much fun together
You're not even aware, you're such a funny pair
You're the best of friends
It's like they are best friends who had just never met. He is eager to show her everything and she is eager to communicate with him. He loves having someone with "black hair and black eyes" like him, and she loves company. He pushes her on the swing, she takes his hand and leads him around the house. They sit together to eat their chicken noodle soup with crackers and pineapple. They share a bedroom. Both love the dog. I have ten siblings and three older children, so I'm under no illusion that they will clash and fight at times, but right now this is everything that I hoped it could be.