Abigail is IN LOVE with her little sister. Neither of my boys felt this way about Abigail. Neither of them feel this way about Hannah. While they like their sisters, they have other things to do.
But not Abigail.
If Hannah is awake, Abigail is aware of it. She is aware when Hannah cries and immediately "tends" to her. When Abigail gets up in the morning, she immediately goes to find Hannah and give her hugs. She truly adores her little sister.
Here is a video I managed to snag while Abigail was not too aware. It is Abigail trying to comfort a crying Hannah.
And here is Abigail attempting to sing Twinkle, Twinkle Little Star to our "shooting star."