One thing we learn when we suffer a loss and sit shiva is to be careful not to say stupid things when paying a shiva call. Honestly, people say the stupidest things you wouldn’t believe what comes out of their mouths. Like asking if the family is putting the house up for sale or mentioning that they have a shidduch for the widow or widower.
Another thing that we don’t realize we say is “i understand how you feel” I honestly we don’t, we can’t because even two siblings are not experiencing the same loss. Because each sibling has their own memories and their own experiences with the nifter or nifteres. So no one is really mourning the same way, and no really feels the same way or understands or experiences the same as another.