Green iquana's quickly outgrow their owners. There are people who have them and maintain them quite successfully, but they're definitely not for the casual reptile owner. That said, she'll have to keep looking or possibly order one in if she's dead set on getting one.
I'd recommend a Chinese Water Dragon, Australian Water Dragon, or Bearded Dragon for the same lizard keeping experience without the 6' long animal that's able to break a dogs leg with it's tail. :shrugs:
D80