What do you think was Jane's biggest mistake in the series?
I think that Jane’s biggest mistake was falling in love at the wrong time. She spent so much time preaching about survival and not getting attached, yet when the group was at its most vulnerable—Rebecca in labour, walkers closing in—she decided that making out with Luke in the middle of a lookout was a good idea.
That moment of selfishness had consequences. The group lost precious time, the deck collapsed, and Sarah died. And for what? A distraction? A moment of comfort? She let emotions cloud her judgment, the same thing she accused others of doing.
And she didn’t learn from it. Later, she did the same thing with Kenny—only this time, it was hatred instead of love. She let her emotions take control, pushing a fight that didn’t need to happen, thinking she could manipulate the outcome of Clementine seeing that Kenny is a dangerous man.
SPOILER BELOW - S3
In a flashback from S3 we see Jane being in a bad condition, Clementine saying that she looks bad, Jane's response being that she hasn't slept well. Clem says that she should get some sleep, so she does just that.
Later when Clem cheeks on her, she find Jane hanging from the roof, after she unalived herself because she was pregnant, shown by the pregnancy test that Clementine found on the floor. This shows us while she was a good survivor, stupid decisions brought her down mentally.
After all I've said up there I think that it was her downfall, falling in love at the wrong time but with the right guy, since Luke was a good guy with good intentions. What do you all think?