Maria Shriver.Nathan Congleton/NBC/Getty ImagesMaria Shriver opened up about a parenting trick she learned from her mother.She said she taught her children to stand up whenever she entered a room, something they still do to this day.Shriver said the women in her family were "big on manners," something she wanted to pass down.Maria Shriver has opened up about the parenting tip she inherited from her late mother, Eunice Kennedy Shriver, and why she believes it instilled her children with good manners.Appearing on a recent episode of the TODAY podcast "Making Space with Hoda Kotb," Shriver, 69, said that she taught her children to stand up "out of respect" whenever she entered a room — something she said they still do to this day."I make them stand up," Shriver said.