Evelyn packed a small bag which should be more than enough to last her for a few days to clear her mind. Henry was yet to return after being out all night dealing with Beth.
This incident was bringing too much attention to the family with all the reports. Henry didn't think to offer Evelyn a call like he didn't consider she would be worried about Beth.
Evelyn wasn't a stranger to how gossip worked and how she would be treated because of what Beth did. She wasn't ready to face anyone asking how she felt or asking about Beth so she was going to leave the building and hide somewhere else.
Evelyn already thought about how angry Henry would be when he came home and found that she was not there. The first thought would be that she abandoned the family but what was she to do? Henry left her here where everyone knew to find them. Beth's presence on social media and Henry's dealership made this report interesting.