okay. teeth whitening question.?

so my 13 year old sister about to turn 14 wants to get her teeth whitened. how old do you have to be to get them like bleached? she won't leave me alone until i ask this. so yeah. ahah. thanks :D
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use the target brand whitening system, it only takes a week and then you have super white teeth and its only like 15 dollars i use it, and i get compliments on my teeth all the time :D
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