“I heard this from my little sister who is 13 years old um she heard this on the playground. Ok so it goes knock knock, who is there? Little old lady. Little old lady who?”
Trying to imitate the sound of yodeling. Making the yodele-he-who sound. Jordan believes when kids are younger and in the developing age, there is a sense of curiosity about the world and finding your abilities within societal norms. By attempting to yodel or in fact thinking that you can yodel kids can feel like a part of something that you would otherwise be disconnected from.
I think little kids like to trick people, so this trap of a knock knock joke easily accomplishes the task. The original yodele-he-who sound is northern European, something heard in the Swiss Alps. Since the teller of the joke is Caucasian she may be from European dissent and this could be a way to relate to her ancestry.