Shih Tzu Q&A
My 6 month old male wieghs in at 45lbs.
That's pretty tall, mine just turned 6 months old an is 39lb and is just under 21" at the withers. By AKC stardards full grown female GSPs should be between 21" to 23" and they should weigh 45 to 60 lbs. So you are going to have a really big one.