aww that's so sweet but sad at the same time. Tell her I said hello!
I think you should take her to a vet and maybe have it scanned, especially if it's a little 9 week puppy!
Also you should be very careful when you walk her, as collies and shepards can be very voilent towards little dogs, as i've had two shepards in the past and i have a collie now, and they always start fights with little dogs and it's not that i'm a bad owner, it's because it's in their nature, so you have to be really careful.
But what annoys me, is that these idiots don't put a mussles (sp?) around their dogs mouth, especially if it's something like a shepard or a collie ;l.
I would take her into see a vet if you are at all concerned. A head injury can be very serous in any dog, never mind a puppy of a tiny breed like a chi!