Before you were born
Michael knew William was cheating on his Mother (Clara) for a long time, but could never get her to believe him because she wanted to turn a blind eye that William was going out with other women and wanted to believe that Michael got the wrong idea with how young he was and that she shouldn't believe her son that her husband cheated on her
William knew that Michael told Clara the truth and at first trying to trick Michael that what he was doing was not wrong and he wasn't cheating, but that didn't work so he started to hurt Michael when Clara left the house to go shop but he made sure that Michael understand that he would be dead if he told his Mother (Clara) on how he got hurt
Elizabeth always put on a happy face for all her family and pretend that she didn't know all the bad thing that happened in her home, she doesn't fully understand what's going on but she likes to fallow Michael around the house like a duckling. Elizabeth doesn't look for her Father approval that much but does what him to know she is there and not air
Chris has seen all his family's deaths before they had even happen that is why he was scared of the animatronicn he saw how Elizabeth died to Baby and that was the start of all his nightmares
Clara just wants to have a happy family and a loving husband, sadly she didn't get her simple dream of a family