Agent Richard07 said:
Another thing... I'm surprised that so many of you figured out that Aaron was her "son" before it was revealed. What tipped you off?
Well, when she first said she had a son, there were two possibilities that went through my mind. Okay three, but the third one didn't make any sense. Either she had gotten pregnant by Sawyer and had his baby, or she had taken Claire's baby (either because Claire was dead or Claire couldn't leave the island for some reason so gave him to Kate to be raised in the real world).
The third one was that Kate had had a child from before ever coming on the island, but it was just way too implausible that he never would have been mentioned by anyone in her flashbacks or on the island, not even slightly hinted at. This was confirmed when Kate was with Claire and said she wasn't good with babies.
This also seemed like foreshadowing that either Kate was pregnant and would have to deal with motherhood herself soon, or that this new friendship between Claire and Kate would lead to Claire giving her baby to Kate somewhere down the road.
Then there was the scene with Sawyer where she said she wasn't pregnant and Sawyer mentioned they had not had sex the night before. It sounded to me like Kate truly knew she wasn't pregnant.
This all tied in with the fact that she didn't want the son at the trial (she obviously isn't comfortable with the whole lying about the plane crash thing).
There was also the scene when Kate was with her mother and her mom wanted to see the grandson. The way Kate responded gave me a clue. We know she dislikes her mother quite a bit for what she's done, but ultimately I don't think Kate is that uncaring that she would forbid her mom from ever seeing her grandson, especially when she was dying of cancer. After all, Kate KILLED someone for her mom, so her love for her mom must run pretty damn deep. So, it seemed logical to me that Kate was okay denying her mom because she knew that the kid wasn't
really her grandson. Also, that's a good reason that Kate would actively not want to have the kid see her mom - because like I said earlier, the whole lying about the crash thing makes Kate feel very uncomfortable, and I don't think she could handle seeing her mom with Aaron, thinking that they are truly related, when she knows they are not.
Of course not all of these details ran through my head as I was watching the show! It was more sort of an instinct or gut feeling about it, and afterwards, going back over the details, it seems more clear why I felt that way.