Thanks for the reports. I will add it to the next bugfix
Until that fix is released, I traced the issue back far enough (to where line 1578 on game\screens.rpy makes the following call
if Visual.FocusContact != Player and Relations[Visual.FocusContact.ObjName].ShowAllure == True:
The true issue is further back, but from here I checked the value of Visual.FocusContact.ObjName and found that it's u'Mom'
The problem is that at some point Mom changed to using her first name (Mary), but that pointer didn't get updated to match.
I worked around the issue it by temporarily typing the following into the console to change the focus to someone else (in this case Lil) :
Visual.FocusContact.ObjName = u'Lil'
This switched the focus and now the contacts screen works again for me. The true bug is somewhere else where this pointer didn't get updated when she changed from 'Mom' to 'Mary'
Edit: Sorry Mary is a different character, that's what happens when a weekend passes and you have a short memory. The workaround is still effective though.
Edit2: Nah, it seems to fix one thing, break another, so I would only do this work-around to view the contacts screen if you need hints on how to proceed, but then reload a save.