Honestly speaking, I think the poor girl's been overworked without any kind of support in her private life and the cracks are starting to show. Since she's unable to frame interactions without applying a business model to them, it's likely that she's been at her job for a while now and she has not been able to take vacations or socialize with anyone outside of business hours. That she reverts to a child-like state as she gets more stressed could mean that she had parents who either actually cared and provided for her or only paid attention to her if she ever started crying or otherwise showing overt signs of stress.
The plushies are a touchstone for her...maybe a coping mechanism from her time in school? Idk, but if it wasn't for our MC-kun over here, I honestly wouldn't be surprised if she was like half a year away from snapping in public and bawling like a baby. She's been holding a lot inside her and she's not able to express those feelings properly because they don't fit what she uses to frame her interactions.