Oh damn, this is actually a really good depiction of autism (my younger brother has aspergers). Never thought I'd see it so accurately conveyed in a manga; for those that don't know, her inability to properly empathise with others is pathological - she's not being malicious, she genuinely thought she was being helpful and couldn't see/ comprehend the negative impact her actions were having (notice her genuine lack of understanding as to why the other girl kept apologizing rather than "simply" using the given "feedback" to change her behaviour). People on the spectrum also have difficulty picking up on social and other non-verbal cues; they can struggle to read the atmosphere of a room and rely on other people to explicitly tell them when something is wrong. (Hence her shock to the revelation that she was being a bully, and her incomprehension as to why no one told her sooner).
As high functioning autists (aspies) mature they learn to better mask emotions (i.e. they learn to better immitate/ fake acceptable behaviours and emotional responses, in order to appear more neurotypical to those around them - while such things come naturally to ordinary people, it takes considerable cognitive effort for aspies to maintain their mask and often leads to increased stress, depression and burnout - notice her mental breakdown when her mask/ the illusion she so carefully created in highschool, crumbled away).
For those interested in learning more, I highly reccomend the movie "x + y" (also known as "a brilliant young mind"). As well as just being a really good movie, it also accurately depicts an autistic character; any viewer will notice there's this one really insufferable character that really stands out from the other kids in how obnoxious and painfully blunt to the point of being cringeworthy, he can be. But by the end of the movie, you just really feel sorry for him and his inability to understand and fit in with other kids his age (despite his best efforts, he just isn't able to act "normal" to a convincing degree).