ears

Question
One of my Aussie's ears is larger than the other. She's 3 months and teething. They both flip forward.  

Also, what's should her size and weight be at this point.

Thank you.

Answer
If your veterinarian has determined that your dog's ears are normal healthwise, and she is not going to be shown in the breed ring, then her ears can be a bit irregular.  Check with your breeder if you have concerns about your dog's lineage producing dogs that have "funny" ears.
The size and weight of Aussie pups varies at this point, and all along the continuum, because they vary in their adult sizes and weights, too.  For example, I have a mature female who stands 19" and weighs about 38 pounds, but her mother, owned by the breeder, is 18" and weighs about 32 pounds.  A six pound difference may not seem like much, but it's a lot if you only weigh 30-something pounds.  I always like to judge a puppy's condition by the body.  Puppies go through some "skinny stages" as they sprout up, but, basically you should be able to feel their ribs without seeing them if they had a smooth coat, and they should have a slight waistline behind the rib cage as in the chart:
http://vet.osu.edu/1851.htm