The 36-year-old former glamour said she would be 'supportive' if Princess, whose father is Price's ex-husband Peter Andre, decided to follow in her footsteps.
She told ES magazine: "I'd never be a hypocrite and say, 'You can't do that,' because I did it. But I wouldn't let Princess have surgery before she was 21.
"I was 18 when I first had my boobs done and it was too young. There should be an age limit."
Currently, patients have to be 18 years old to undergo elective cosmetic surgery, according to The British Association of Aesthetic Plastic Surgeons, but they will be considered from 16 with parental consent.
Mum-of-five Katie - who recently reduced her size 32FF bust to its original size 32B - has had seven breast augmentation surgeries, as well as a nose job, lip implants, liposuction and teeth veneers.
She recently said that if she was Prime Minister she would increase the legal age from 18 to 21 to go under the knife.
Now she's done with going under the knife - but happy to have Botox treatments to keep her wrinkle free - and wants to expand her family.
She said: "I want as many as I can have before a doctor says 'no more' and then I'm going to adopt.
''I'd like to come down one day and have 10 kids sitting around the kitchen table - that, to me, would really be success."
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