Change in behaviour. Or physiological?

My mother has been a single mother as long as I have known. Recently in middle of the covid pandemic and lockdown, we were confined to our house and never ventured out . Few months into the lockdown my mom started showing some behavioural change as someone is plotting bad deeds against us ( in our life we have predominantly seen bad situations so ) ,and then it has escalated , she keeps hearing someone talking ill and physically has lost so much weight.All in all she has lost the vigor in her .We are 3 sisters and we tried talking to her alot but to no alas ,but all boils down to the safety of us ( since we are girls in this current "women safety" situation ) . Ps: she has been a strong lady her entire life . Please advice as to what has to be done , is this purely psychological or physiological ? And please let us know what exactly should be our course of action . Any advice or help would be immensely helpful . Thank you so much in advance .