Sister is way cooler: Check
Previously engaged to a Lannister: Check
At one point was in love with a monster (Baelish/Joffrey): Check
Needs to be shoved out of the Moon Door in the Eyrie: Check
I think we are being a little harsh on Sansa here. She is a brooding teenager who may be naive, but she isn't breastfeeding a thirteen year old at court. Let's give her some time.
Reading the books I like where Sansa's story line is going. So I think she earns redemption which I won't get into. Or maybe I jut have a thing for damsels in distress.
Also, although the character on TV looks older like 18, this is medieval times of a sort, she just got her period like two episodes ago - she is supposed to be like 13 or 14, and was eleven when first introduced at court and to Joeffrey.
She is a female, whose primary purpose in life is for marriage(political alliance) and having children, and primary learnings were not espionage or treason, but household management. She was trained to be the dutiful wife of nobility and raise children, while the males like Robb were trained in battle, espionage, and politics.
Give her some time. Trial by fire is often the quickest way to learn.
And what 13 year old swoons for the smart man. Loras Tyrell is basically Justin Bieber.
Sansa is still holding on to the faerie tale at this point. Sure, her dad died because she sang like a canary just because Cersei asked her to. Ok, that's a crack in the mirror that is her image of her life. Sure, the Prince of the story has turned out to be a sociopathic monster who will, given a chance, make Aerys look like Rheagar. That's another little crack there. She's been beaten a little bit, so that's not cool....
But look at her reaction when the Tyrell's show up. She tosses her fate into the hands of a group of women she'd never met before, who had betrothed their mini-Cersei to not one, but two kings at this point. They'd switched sides at the most opportune moment possible during the Blackwater. She had no reason to trust these people, and plenty of reason to at least be wary of them. But, one offer of nice cheese and a refreshingly tactless grandma later, she's speaking ill of the sitting king to his future wife and grandmother.
And then, when the Tyrells whisper tidings of letting her marry Loras, she goes back to being all moon-eyed. Not a single lesson learned on her part from having GOTTEN HER FATHER MURDERED. She'd never been in the same room as Loras, but DING she's back to being a princess being saved by her shining prince in armor. She is back to waiting for her Florian. Not once did she ask herself why they'd want a traitor's daughter to marry one of the most eligible men in the realm, because that's a question that, to her stupid mind, doesn't need answered: she's a lady, and he's a knight. This is what happens.
Additionally, she knows that the Queen places hand maidens with her to spy. And yet, even after being told that she has to keep the Loras thing quiet, the first thing she does is spew frothy stupid all over Shea's ears. If Loras hasn't spilled the beans, Littlefinger or Varys would have been able to learn the secret just by mopping up Sansa's bedroom.
At this point in the story, she's more insufferable than she was when she got her dad murdered. She hasn't learned a thing. I forgive her nothing nor will I pull any punches on the Sansa we have right here and now in the series.
Guys, and Gals. Sansa is a 13 year old captive of the Lannisters. She saw her father beheaded and has not seen her mother or a family member in years. She is surviving and still has a dream and hopes she can come out of it OK. That's pretty admirable IMO. I mean, I like Arya, but she is handling it better? She is planning on murdering everyone who has ever wronged her in any way. This is a better strategy than becoming the wife of the Heir of House Tyrell? Can't defend her trusting Cersei Lannister, but she is hardly a villain. She is guilty of being a romantic, and the story can't just be all blood and guts. Also, Sansa is doing what Ned would have wanted, Arya is not. Ned is still the moral compass of honor in the story.
I also blame Robb for Edmure's battle mistake. If Robb would've actually let him in on the plan, he wouldn't have gone and attacked the Mountain and the Lannisters. Then Robb blames him for messing up the plan - Robb's fault.