Hello, I Recently Adopted/bought A Shih Tzu Puppy, However After

Hello, I recently adopted/bought a shih tzu puppy, however after seeing pictures of her at six weeks I am concerned that her head appears unusually large. Additionally she is rather "wall-eyed" and seems (from the photos) to be a bit disconnected - I will be contacting the breeder but I am wondering if I am just worrying too much - or if these sound like symptoms of a bigger problem...