Lucy mentions her Aunt Marion on various occasions. On the first occasion, Lucy has failed to talk Schroeder into the idea of marriage, irritating him to the pint where he leaves the room. Annoyed, Lucy turns and mutters "My Aunt Marion was right. Never discuss marriage with a musician". On the second occasion, (October 10, 1980) Lucy tells Schroeder that her Aunt Marion told her not to fall in love with a trumpet player. When Schroeder points out that he doesn't play the trumpet, Lucy smiles at him and asks how she knew she meant him. She then turns and smiles, thinking she has successfully confused Schroeder.
In the strip from June 2, 1991, Charlie Brown sees Linus walking along with a blanket in his mouth. When he asks Lucy if it is Linus, Lucy replies that Aunt Marion says "you can choose your friends, but you can't choose your relatives". Interestingly, in the strip from October 12, 1982, Charlie Brown tells Peppermint Patty that his Aunt Marian told him the same thing. Whether or not they are two separate Aunt Marions is to be debated.