I know there is some research showing that some GT kids really do need less sleep, but given the vast number of kids I know whose parents say they "need" less sleep, I would try harder first to work on getting her on a schedule or finding the sweet spot for nap and bed timing. There is a TON of research out there on the importance of sleep. If this one doesn't need it as much, then she is still affecting the rest of you. Maybe you can rejigger the sleeping arrangements somehow? Sometimes kids actually need to go to bed drastically earlier. If all else fails, then YOU should go to bed drastically earlier or find ways to get rest otherwise. Your 3yo also should not have to have his/her sleep interrupted.
I personally am not a fan of the "it won't last forever/this too shall pass" advice. I have seen too many families really struggling under the stress of kids not sleeping well, sometimes even past the age of 6 or 7. Marriages can be harmed and parents (usually mothers) cannot go out at night, etc. I don't mean to be doom and gloom but I really think this is important to work on.
