Interesting and well-written post!
I get the feeling that more than anything, Anandi is plagued by the idea that there was some kami in the way she fulfilled her duties as a wife. As a child, Dadisa was never happy with her and always favoured Jagya. Dadisa may have changed now, but the wounds that that sort of treatment from her inflicted on Anandi are yet to fade. I'm not saying Anandi feels resentment towards Dadisa... I think her resentment is purely for the culture that has encouraged bal vivah... hence her work to stop it and save other children from the fate she herself suffered. But despite not feeling any resentment towards Dadisa and the rest of her family, she is still psychologically wounded by the thought that she was somehow not good enough for Jagya to stay with her. Logically, she knows that he is the one at fault, but emotionally, she still blames herself on some level.
I agree that attachment does play a big role, though. She grew up being told that her husband was to be her everything. She was essentially taught to treat him as more important than her own self. Now that they are no longer together, she has been growing out of that and growing into herself a lot more... getting an education, doing samaj seva, becoming a strong member of the community. But part of her is still that girl who believes that all that isn't enough, and that she is still defined by the fact that her husband left her and that that says negative things about her capability as a beendhni (and therefore as a person, because it was impressed upon her as a child that a beendhni wasn't just what she was, but WHO she was). Add to that the way Jagya was putting her down for being "gawar" and you get serious self-doubt. Plus, I mean, her relationship with him wasn't just based on duty - they had a close friendship, and he did like her at first. The betrayal of all that must seriously sting as well.
The only thing I disagree with in your post is the teddy bear analogy. I think that is more apt to describe Jagya's feelings for Anandi... as a plaything to use as and when he wanted. He has never really seen her as a person... more as a beendhni who he has a right over. He does care for her, and that's shown in flashes, like when he ran off to Jaitsar to save her from Heth Singh and the kidnappers (lol, that sounds like a band name... Heth Singh and the Kidnappers
ANYWAY). So yeah, he does (or did) care for her, but his spoiled upbringing and MCP-ness comes in the way of that most of the time. He has certainly never appreciated her, or really been thankful for how good he had it to have a wife like her. Rather like with a teddy bear... a new toy (Gauri) came along and the old toy suddenly seemed dilapidated and unattractive
Whereas Anandi's feelings were much more serious... there was much more devotion there. In short, she was much more invested than Jagya than he was in her, because that's how the culture taught her to be. And because that investment was so great and spanned so many years (and part of her childhood), it's that much harder for her to get out of it.
I believe that as she realises what Shiv feels for her, starts feeling for him herself, and realises what love really is, she will realise that what she had with Jagya was never truly love, but just two incompatible people being thrown into an attachment before they had any say in the matter. She obviously knows that logically, because she keeps saying it (e.g. she told that bal vivah supporter at the press conference that a husband grows up and barely even remembers his wife's name). Like all the other stuff, though, she needs to really REALISE that on every level and stop blaming herself deep down. And she needs a LOT of time to get to that stage, though. Let this divorce happen, and then we will see.
AnSh should be a conscious choice from both of them based on a deep mutual love and respect, and should embody equality, compassion and attraction. They should serve as a misaal for viewers that THIS is how relationships should be, THIS is how partners should treat each other, that abuse, even if it's not physical, is NOT OK, that compatibility is important, that a girl who's been treated badly can and should start her life over. And crucially, much as people may not like it, Anandi taking her time over this whole thing and not immediately jumping into Shiv's arms just because she's lonely and he's a hunk is also important to this message: it shows that one should take one's time over relationship decisions. A girl shouldn't immediately go with anyone who's nice to her just for the sake of having someone. She should be OK with herself first, wait until she's ready, make sure (or as sure as she can!) that the guy is right for her, and THEN take the plunge. People should realise through watching Anandi that it's OK to wait, because the right guy will understand and hold out for you, and your relationship, when it does happen, will be stronger for that