That is true. Unless there is free wifi I don't know about you will have to purchase it. If it was a 3G enabled phone she would use the cellular network but since it is an iTouch and not an iPhone she can not.
If you are staying at one of the deluxe resorts, some of them have free wi-fi in the lobbies; YC does and a think a couple of the others - check the resorts board for a complete list.