Mine is "off the charts," too, and both parents were in between 6.5 and 7 lbs.
At 9 weeks, she weighed 38.4 oz.
At 10 weeks, she weighed 50 oz.
That's a gain of 30%
in one week. That would be like a teenager going through a growth spurt and going from 100 lbs to 130 lbs in one week, skeleton and all.
Every week except for two her growth rate (%) was in the double digits. At 15 weeks, she was 91 oz, tomorrow I weigh her at 16 weeks, who knows how much she will have grown then.
I brought a spreadsheet with her weekly growth and % growth per week to show the vet, he just laughed and said "That's amazing!" (Maybe he was laughing at the geeky pet owner that brings in a spreadsheet with growth rate calculations, I dunno). He said it wasn't a problem in small breeds, but would be a problem in larger breeds.
She is definitely thriving and healthy, and since she is a companion and won't be used for breeding, health is the primary concern and larger and sturdy is fine.
We are thinking of changing her name to "Yorkzilla."