Could beardie by a rankins?

We bought what was sold to us as a bearded dragon in May. She was supposedly around 3 months old and 9 inches then and is only 12 inches now. Other dragons that we've bought at that same size/age have grown on average an inch a week. What's wrong with her? She is housed just like all the others . . .

Could she be a lot older than we think? Could she be a rankins? Or possibly a hybrid between a bearded and a rankins?? Thank you for you suggestions!

she is probably a slloooww grower, we have a female that is a year and hasnt broke the 13" scale yet! We have her brother too that is a year and has broke THE 15" scale by almost 1/2 an inch.I bought a beautiful yellowx citrus female and she has broke the 15 1/2 " ( 1 yr old ) scale and is still growing, they r just like us people..all r different than the other and grow, eat, sleep, move and well sit around different than many others. I dont think you have a rankins due to the fact of the bright orange color she is..rankins that I know of havent been seen in any other colors than brown and tan...thats just what I know and hear, but once again IMO she is maybe just a slow grower. Mike of REBEL DRAGONS ( GOOD GUY!!) has had dragons that never broke 8" and they were adults!! I havent seen them or anything but I believe him knowing our littlest girl hasnt broke 13" and is a year old!!