When I was expecting Babs, often people would ask Kiddo if she was excited that she would have a little sister she could play with. She was, but then, it turned out that her little sister could not only not play with her, but also took up a ton of her parents attention in addition.
But Kiddo is an excellent older sister, and put up with the intrusion in her life, and now doesn't remember life before Babs. And their relationship has changed over the last few months. Now that Babs walks, and communicates (some signs, some words, and lots of personality), they do play. And they play a lot. And they really enjoy each other, most of the time.
The other day Kiddo insisted on holding Babs' hand (much to Babs' dismay), insisting that "holding hands is what best friends do." I don't suppose the road will always be smooth, but I hope by the time they're grown up, they can still be best friends.
(Hey, did you notice the milk cup in Babs' hand? Yeah, I abruptly weaned her 2 1/2 weeks ago. She woke up in the middle of the night again, and I said: you're done. With serious support from my husband, she never nursed again. After 48 hours, she actually seemed relieved that we'd put our foot down... Kind of like making her sleep through the night. I'm loving it.)