Depending on the physical size of the person, some 14yr old kids are already over 6'' and exceed 200lbs, BP varies.
But on average, if an average 14 yr already has a BP of greater than 110/70, the chance of developing high BP later in life is high. So, do what you can--keep ideal wt, eat healthy
, exercises as much as possible, and don't smoke. If u r concerned, consult doc. Good luck.