I don't have a comment on how big your girl will get, but I will comment on you running a three month old puppy for an hour every morning. That is really not good for her growing joints. If you meant that you let her run around at her own pace on a soft surface (grass), please ignore my comment. But, if you are running her at your pace on a hard surface at this age, I strongly recommend you stop.
She's a real cutie. Best of luck with her!