She pretty much chose the worst possible time to actually do some self-reflection like this. Though considering her mother, I doubt she would have been allowed to visit a therapist or counsellor for any advice.
Epiphanies and crash-outs rarely occur by choice xD
The first step to getting a better situation is realizing just how shit your situation was in the first place. Problem is, that includes getting hit with all the emotion you've been repressing to get through it. It took the Afterschool for Maaya to find a place where she can be herself, which reopened her struggle with feeling like an empty doll, which led to realizing just how suffocated she was under her mom's influence.
I think Maaya's apparition causes her to get "sick" - that is, spiraling more and more into negativity - the more she looks at it? Like how MC's ghost used his artistic meticulousness to try to lure him off the roof.
I am curious how her sudden death's gonna change the group dynamics. Would MC blame himself and be haunted by a new ghost taking advantage of that guilt? Is someone gonna be manipulated by a ghost to continue blaming MC? And what does a ghost "being born" in the real world actually mean in practice?
Imma gonna chew out the MC Kei here for a moment, because his cynical ass arguably tipped her over the breaking point and contributed to her suicide/ghostmurder rather than slapped her back to reality. He did the exact opposite of helping here.
TBF to the MC, it's not like he knew she was troubled by this. She's a minor celebrity. It makes her vulnerable to obsessive fans and manipulative competition. Keeping up an image or persona, or putting some distance between herself and others is practically expected behavior.
(Plus, he just had a near-death experience that dredged up memories of abuse and his own suicidal ideation, after a stressful week or so. Of course he's gonna be a bit cranky when someone asks him to draw them right after that.)
(Which. I actually love how the individual struggles interact and interfere with each other. Kei being a positive influence for MC, while MC worsened Maaya's spiral.)