So using other objects for reference...she is twice the size of an Xbox360. Looks fine. These dogs all grow at different rates and at different times. Some have growth spurts early, others have them later on. The slower they grow, the better. Also depends on her genetics...she is a female so she should max out around 70 lbs...I prefer them when they're smaller than 60. Do you know the size of the dam? That will give you some clue as to how big she'll get.
Weight is the most important thing right now. Not too skinny, and make sure she's getting enough food/calories that she has the ability to grow. From the picture, she looks perfectly healthy.
thanks for the comments!!! mum was about as tall as dad and he was quite big
this is dad:
obviously id love her whatever her size but i do like the bigger end of the spectrum.
it certainly hasnt helped seeing a pup who was 3 weeks younger and he was huge!!! but she is healthy and now 18 weeks measuring 18" at her shoulders so not big but like you said maybe just a slow grower
She looks lovely looks about right but can never tell how gonna emd up my romany was runt litter tiny in size and now shes as big as my male gsd kane and hes 28 inches at shoulder shes same height but longer in back and thats big for a bitch so goes show can do complete turnaround where growth concerned just make sure has vitamins they need and shel be fine shes lovely though