Board for my little girl

Anyone give me a quick bit of advice on a suitable board for my 11 year old daughter? She's hooked on surfing but in reality she'll only get near the Devon/Cornish coast for 3-4 weeks a year-maybe a bit more. She's a lightweight at around 37kg.
I've been advised to go for an NSP 6'4" fish as a board that will last her a good few years, bearing in mind she'll probably be in the whitewater most of the time-Good advice or not?
I've been advised to go for an NSP 6'4" fish as a board that will last her a good few years, bearing in mind she'll probably be in the whitewater most of the time-Good advice or not?