Sarah's story seems to be the one most likely to follow a different path from the first time round, so to speak. Knowing that her relationship with her husband will fail, and she will end up marrying her boss must put an enormous strain on her - on top of the worry about her son. I mean, if you knew you were going to fall in love with someone before it happened, isn't that knowledge likely to stuff it all up.
I think her son will die, her husband will leave her (possibly before her son's death this time), but she will not find happiness with her boss, and perhaps her chances of getting onto the shuttle in 2007 will fade altogether... What happens if none of the crew end up on that shuttle? It is easily possible - Kurt is probably the only one who hasn't already had his chances possibly ruined.
I think her son will die, her husband will leave her (possibly before her son's death this time), but she will not find happiness with her boss, and perhaps her chances of getting onto the shuttle in 2007 will fade altogether... What happens if none of the crew end up on that shuttle? It is easily possible - Kurt is probably the only one who hasn't already had his chances possibly ruined.