Ok all you movie buffs.. Need your opinion !?

The way it is done is not definitive, and James Cameron himself said it was open to interpretation. Personally, I think she did die, after she has dropped the "Heart of the Ocean" where it belonged, with the one who she loved for so long died. Additionally, Jack does say, "you're going to die an old lady, warm in your bed," and remember the spitting scene? They talked about all the things they'd do together. Near her bed-side, there were photographs of her riding the horse, with the roller-coaster in the background, just like Jack and her wanted to do together. She kept her promise to Jack, to never let go. She also hadn't spoken about Jack, to anyone, until then. Her mission/story was essentially complete. Not only has she returned her heart where it belongs, but she has done what Jack had wanted for her. I believe at this moment, she dies "old in her bed" and returns to her heaven, and joins the rest of the people who perished in the tragic Titanic incident, and most importantly, for her, has returned to her true love.