What is an average weight for a 12-year-old girl who is 5 feet 3 inches?

my daughter is twelve and shes kind of athletic,but then she can polish off a big mac,fries and shake in nothing flat lay down ,take a nap and not gain a pound,holding steady at 100-105 lbs 5'4" .me on the other hand if i even look a the couch is the difference between a 36" and a 38" waist:)