When Ellie learns to crawl I am 100% positive it will be in pursuit of Sophie. Three years ago we went to a local shelter looking for a kitten, but the fully-grown Sophie practically jumped out of her cage and made clear her intention to come live with us. Since then, I can't believe such a love-bug ended up in a shelter in the first place.
Sure, her razor-sharp claws are destroying my furniture...but I honestly don't know how so much love fits into such a small cat. Sophie wants nothing more than to adore her humans. She would rather sit on your chest than your lap, purrs loud enough to disrupt your TV watching, and would happily ride around on our shoulders if we would just learn to walk slowly enough.
As Ellie's interest in her surroundings has grown she's become absolutely fascinated with Sophie. She grins like a fool and squeals with delight every time the cat comes near. She bangs her little fists about Sophie's head and pulls out handfuls of kitty fur as she clutches at her. There is no "gentle petting" in Ellie's vocabulary. And Sophie? She sits there purring, loving every second, and only walks away when Ellie's abuse becomes particularly torturous.
So here's to Sophie, designated Ellie plaything and sweet companion. Poor kitty. If only she knew how bad it's going to get once the kid is MOBILE.

P.S. And what about Topaz? Our elderly curmudgeon doesn't express much interest in Ellie, and since he's been known to nip we don't encourage Ellie to pet him. So far, they pretty much ignore each other.