Hi, Generally dogs take their full size in 8 to 10 months & bitches have small bone structure in general. If you still think she is under size try then you need to answer the following questions to yourself & think further what you can do. Did you pick up your pet from a breeder? Did you see the Dame & Sire of the puppy? Did you read/ researched enough before deciding upon the breed? Did you take your pup to the vet for structural examination? I think you should also speak to the breeder & see how they respond.
On the other hand if you didn't get your pet to show at dog shows it shouldn't matter, because she will love the same.
Some dogs, like a lot of good things. just come in small packages. I think manoor is right, did you see the parents of the puppy? Did they have a smaller build? My advice to you is if your GSD gets a green card from the doctor as far as all health checks and vaccines are concerned, you shouldn't worry too much about its size. I assure you, she doesn't look at anyone else's head before wagging her tail :) Good luck!
its true tht u shd cheque with mother & father of the pup because .by 8 months of their age they become mature & ideally should grow completely. after that there is a steady growth period.which is a maintenance phase of their life.some other factors regarding the proper growth of the dog are regular deworming, Adequate & nutritious diet, proper exercise.