Where's Sally?

jean:Where's Sally, Jack?
jack:She's in the garden, Jean.
jean:What's she doing?
jack:She's sitting under the tree.
jean:Is Tim in the garden, too?
jack:Yes, he is. He's climbing the tree.
jean:I beg your pardon? Who's climbing the tree?
jack:Tim is.
jean:What about the dog?
jack:The dog's in the garden, too. It's running across the grass. It's running after a cat.