Does she already have an ipod? In which case my answer would be no. 2 days before a big trip - I would not want to spend more money on a new or refurbished ipod.
If she doesn't already have an ipod - and you get a new one (refurb or new) how much would be spent on i-tunes to make in a short period of time to establish her play lists?
Sorry - I would have to veto this request. Mostly because 2 days before a big trip - who has time, not to mention the money. The DD should have mentioned this about a month ago or so, in which case my answer might have been a bit different.
ETA - If you are not taking a computer with you - you'll probably need a wall charger. And - assuming you will be traveling for a fair amount of time to get to Hawaii, "tune juice" isn't a bad idea either! I do have a teen - and while we keep her fairly technologically current, I couldn't even imagine taking her on a long trip without an ipod.