I know we talk about Armin, and the confidence he gained throughout the series an awful lot, and it is very interesting character development, but the person whose development tends to be overlooked is actually the one whose is the most interesting: Sasha.
Let’s see; Sasha starts off as the slightly dorky kid, a bit goofy, but she’s also rather insecure. Like, look at her behaviour around Ymir; she goes along with Ymir’s demands, calling her ‘lord’ etc. and bowing to everything. She didn’t really have any need to do so, as I am ninety-nine percent certain that if she’d stood up to Ymir - who wasn’t really doing anything wrong either way, but who was making Sasha her servant for fun - nothing else would have happened. Instead, Sasha went along with it, and I think that stemmed from insecurity and desire to be liked and accepted. She even saluted Ymir and Historia - then Krista - during one of the dining room scenes. It shows just how little confidence she had at the start.
She’s also insecure about her accent, as we saw during the chapter in which she rescued the little girl from her village. Coming from a small community in the throes of famine, you can imagine that Sasha had quite a sheltered life. I have conflicting feelings here; on the one hand, her father seems like a fairly integrated part of the village. On the other, if Sasha really had grown up in Dauper then surely she’d have been recognised by more people when she joined up with the train of horses? It’s a possiblity that her father only began to get more involved with village life afterwards, but Sasha did always introduce herself as ‘from Dauper village’. Either way, I don’t think Sasha ever had much of a social life in and of itself; sure, she probably chatted to people her own age and stuff, but my impression of her past is that she never had any particularly close friends. This is based off only a few panels, but it seems to have been just her and her father for a lot of the time. Dauper probably experienced a high death toll during the famine, and was then repopulated with the refugees from Wall Maria; there seems to be a certain level of emnity towards the survivors of the Titan attack on Sasha’s part, which probably led to a slight disconnect between her family and the village.
Sasha’s a bubbly, sociable girl, but I think her father was her social support, rather than a large amount of friends or family. Though she probably wanted to make friends and has always been rather out-going, she also seemed a little in awe of the more outwardly self-assured girls like Ymir, who at least projected an aura of self-confidence, and Mikasa, for whom a lot of stuff is so effortless that she probably seems self-confident without even trying. That’s possibly why she’s friendlier with Connie than the others, though they all seem to have a relatively close bond, because Connie is a little more normal than the rest of them.
Sasha starts off as friendly and sweet, but there’s always a level of insecurity and awkwardness there; she tries to fit in more than be herself, and I think this is in part because she isn’t used to being around so many people of her own age. Her outward projection of goofy fun-loving foodie means that her lack of confidence and then her character development and the way in which she learns confidence is somewhat masked. It’s a gradual thing, which we don’t really notice until we go ‘woah, look at how badass Sasha’s become’.
I’ve always wondered why she never showed off her talent with a bow and arrow beforehand; while I doubt the army would ever have trained with them, because they’re useless against Titans and guns are a more effective crime deterrent, presumably the opportunity to practice aiming came up every once in a while and Sasha has pinpoint aim. Possibly she’d have thought a bow and arrow would seem out of place in the army, or maybe she didn’t want to have questions asked or something. But it’s fairly symbolic that her growth in confidence came after she picked up that bow and arrow to save the little girl.
Of course, there were other factors too; she made peace with her father, who always indirectly contributed to her insecurity - I am convinced he loved her and that their relationship was close, but we can’t forget that they clashed on several points, and she seems to have been waiting ages for her to tell her that she’s become a ‘fine woman’.
But I think Sasha’s self-confidence comes from her accepting her past. She’s always spoken formally rather in her natural dialect and denied her roots. By picking up the bow and arrow - I’m discounting the hunting OVA here because that’s just a bit of fun for us fans really - the weapon with which she hunted when she lived with her dad in her village, she became more in tune with who she was and merged her former self with who she is now. It was an instinctive reaction, definitely, but she seems to have just continued along with using a bow just fine afterwards.
Her dad’s affirmation of who she’s grown into played a huge role in this, in my opinion. She’s become someone different, that’s for sure, and he’s proud of that. There no longer needs to be a clash between who she was and who she is now; there are more important things at stake, like protecting children from Titans and doing her job and her dad knows that and is proud of her for it. She’s reconciled with him and it does wonder for her confidence.
I don’t think Sasha necessarily ever had low self-esteem; she always seemed like she had a fairly good opinion of herself without being conceited, but just never appeared very secure in herself. It was more of a desire to be recognised outwardly by others rather than a need to be recognised by herself - very similar to Armin in that sense.
The scene when the gang are rescuing Jean and Armin is very telling; not only does Sasha show off her badass bow and arrow skills, she reprimands Mikasa and refers to the merchants as prey. She’s perfectly open about how she used to be and her roots now, and it shows in how she treats others. I’m not saying she automatically became a bitch and started snapping at everyone - because she didn’t even snap - but she gained the confidence to tell Mikasa, of all people, the girl who graduated top of the Southern 104th and who used Sasha as a bit of a butt monkey, albeit without intent to hurt her or cause offence, that she made a mistake.
While Armin’s and Jean’s are the character arcs most people talk about, and that are stressed on the most in canon material, especially the anime - in my view - there’s no denying that Sasha’s is just as important and just as interesting.