I'm convinced that one of the women in the Looking Glass (the dark-haired one in the back, who appeared a bit older) is Annie, Ben's girlfriend from the Dharma Initiative. Juliette said that Ben told everyone that the hatch had flooded, so it appears very strongly that he is hiding them in there and doesn't want the Others to find them. This would make sense if Annie had refused to join with the Others during the purge, and Ben decided to protect her by hiding her away in the hatch.

This then raises the question of who the other, blonde, younger woman is. My guess -- she's Ben and Annie's daughter. I'm not sure if the timeline works, but perhaps they had a daughter, and then the purge came, Annie refused to betray the Dharma Initiative, and the Others told Ben he had to kill her (but of course keep the baby). Perhaps this was at the same time that Rouseau arrived on the island. So Ben hid Annie and her daughter in the Looking Glass, kidnapped Alex, and told everyone he'd killed Annie and that Alex was his daughter.

Of course, that begs the question of why Annie could have a baby on the island but no one else could. So the theory isn't perfect, but I'm about 99.9% sure of the Annie part of it.