You have every right to be angry but it sounds like you are taking the perfect approach. If you forgive her and move on you'll be much happier. What she did was without question designed to serve her own purpose but in the end you have a wonderful little girl that has just as much chance at being the smallest adult of the litter as being the largest.
I have raised this breed long enough to know that you are going to be surprised more often than not at which puppy winds up bigger and which one is smaller. We think when we see a little one compared to his littermates that he will stay smaller, but just as often he'll be the biggest adult.
With her beautiful face (from your pictures) and her wonderful temperament (from your description) it sounds like you have a delightful little girl at any size. Knock the dust from your sandals and leave the deceitful experience behind so you can truly appreciate your new furbaby. It's a lesson learned and you are the better person.
