HEADMASTER: Like mother, like daughter.
LORELAI: Okay, hold on.
HEADMASTER: Ms. Gilmore, active participation in Chilton activities for a parent is vitally important.
The phrase “like mother like daughter” can be found in the Bible, in Ezekiel 16:44. There, it specifically refers to the city and people of Jerusalem, who are said to have the Hittites as their “mother”. It isn’t complimentary, meaning that Jerusalem has taken on the same disgusting practices as earlier cultures, despite the love and protection of God. The proverb seems to have been well-known even in Old Testament times.
You can see Headmaster Charleston in the role of disappointed God, having offered the love and protection of Chilton to Rory, only to find that she has inherited her mother’s appalling habits!
This is where this episode’s title comes from.
The Annotated Gilmore Girls 