Based on the flashforward they'll be off The Island before she should die

No, she's too much of a central character. But if the rumours about a main character dying are true, my bet's on Sun. I think the writers wouldn't kill her off though, she brings in too much views from the Korean airings to be killed off.

KOREAN POWER!!!!!!!! ... yes i am korean

I think that either Juliet will find a way to save her or they will leave the island before she dies (or possibly a combination of both). There aren't that many female characters on the show, so I don't think they'll kill her off.

Going by the length of time that has passed in the show over half the series' total run, her pregnancy shouldn't come to term until near the end of season 6... so her fate could be tied to the island in a very strong way.

really hope not because jin without sun would mean jin would b strange