In S1E4, Rose tells Blanche she's never heard of anybody who hates their own sister, and yet she hates her own little sister in this one.
Gary's left arm changes position on the couch when he hits on Rose.
In season one, Rose's mother comes to visit. In season four, Rose's little sister comes to visit and Rose catches her with Blanche's boyfriend. She tells Sophia, who doesn't believe her, and Rose says "I swear on my mother's grave!" No mention was ever made of her mother's death, although it is possible the death happened and was simply omitted from the storyline.