I don't know why they disregarded a prequel right off the bat. First of all, the title meaning "Sea of Dreams" could have a reference to "Field of Dreams" or in other words "Build it and they will come". Sure the girl all grown up appears to be "older" but who's to say that's her, or who's to say they aren't taking a slightly different design to steer away from the complications of killing "kids" in the original.