I think exactly that,Hartley.
I've seen mentally ill and most are so down that they don't socialise in any way,and barely leave their homes let alone go to clubs and parties,etc. That would be the last thing on their minds. That's mentally ill. These poor souls can't be bothered about their appearance,let alone paint their nails or even think about enhancements of any sort. Yes,Sheila was crying out in a way,but went the wrong way about it as well as in the wrong direction because nobody understood her. Sadly,in the end,she made sure she'd be recognised and listened to. In other words her frustration built up like a pressure cooker and she blew.
The " shaking " bit with Sheila could have been the effects of noxious drugs and not prescribed medication as would have been mood swings which also occur before and during the PMT stages. Women are violent during PMT alone without the added drugs to exacerbate it. Drug withdrawal encourages violence too,whether it be from prescribed or otherwise.