Well since you asked that in an LH-Forum it was obvious that everyone will tell her NOT to cut it since she has very long hair.

Personally, even tough i like long hair myself alot, i would say cut it. She has long shiny hair, thats true, but its very thin as well and does not have much body to it.

With shorter hair it would look definately fuller and healthier then it does now, wich might be better looking then "only" long hair...