As a New Game+ option sure. As others have said, it'd totally ruin the story if she was alive the whole time, but as a party member she's really unique in terms of her healing limit breaks and has superb magic and so it'd be nice to have that extra choice for making up your party. It'd be fun if they made people go through a load of convoluted and ridiculous steps (drying up the Forgotten Capital's lake with 99 tissues for one!) to do it.