My tiniest puppy bitch ended up as the biggest bitch (and one of the biggest pups of all) at 70 lbs!
I'm not sure what she weighed at 11 weeks, but she couldn't have grown THAT much that quickly after I handed her over at 8 weeks. And yet she obviously ended up quite large (though lean) in adulthood!
Provided with good nutrition and exercise she'll end up at whatever weight she's genetically programmed to be. Keep her fit and enjoy her!
Kathryn Saxon
Daisax Boxers