I have been wondering about alternative LA, and have an absurd guess. Below the fold, that is, or after the jump, or whatever.
Who is the mother of Jack's child? The obvious answer is Sarah, played by Julie Bowen. She was recently in Hawaii for the making of Modern Family's episode there, so she should have double-dipped.
Another possibility, perverse as it is, would be Juliet. We have not seen her yet. She is probably going to have coffee with James Ford, but she could have married and left Jack in alt-LA before she moves to James. That would parallel how things played out on the Island.
Is this absurd? Am I crazy? Answers to those questions do not have to be related.