I'm sure they could find some reason to bring her back, if they wanted to.
Will is unhappy with the prospect of living forever as the captain of the Dutchman, because he'd have to watch Elizabeth grow old and die. He teams up with Jack Sparrow to find the Fountain of Youth, with the intention of using it to grant Elizabeth eternal life. When they reach the Fountain, they find that it only works once every five hundred years, and each time it only provides enough water for one. Jack wants immortality for himself, Will wants it for Elizabeth, wacky hijinks ensue.
Also, at some point someone slaps Jack. Also there'll be a monkey. An undead one.