What is the connection between Sex and the City and The Carrie Diaries? Is it Carrie Bradshaw's childhood days shown in The Carrie Diaries? If so what happens to Carrie's sister in The Carrie Diaries? She is never shown in Sex and the City (not even for her wedding).
The Carrie Diaries (TV Series) is a prequel to Sex and the City. It is based on the novel The Carrie Diaries. You are right that Carrie Bradshaw's story is being told in the TV series, but I am unaware of the novel's story, so can't tell you what happened to Dorrit. But in the TV series it's in the second season and very few episodes were broadcast yet. So it's too soon to speculate why Dorrit Bradshaw didn't attended the marriage and where she is in Sex and the City.