Blocked communication with an abusive former trustee and co-owner

This question is submitted by Adriana W. out of Massachusetts

A former trustee and co-owner who stepped down is abusive to me. We now communicate only via a special email I established for her (as opposed to my personal email), which I respond to every few days but not daily. 

I had blocked her from my personal cellphone due to the harassment. She claims I must keep my cellphone available to her (I pay for my own cellphone, of course). 

There are other trustees besides myself but we are in the same building. She can contact the property manager we hire for emergencies and does so routinely, including if there is an issue of something malfunctioning. 

Do I have any responsibility to a resident vis avis my personal cellphone? If I must, I will unblock her for certain daytime hours.

Thoughts?