Fourchette is where
Labia minora are two thick folds of skin devoid of fat, on either side just within the labia majora

Anteriorly they are divided to enclose the clitoris and unite with each other in front and behind clitoris to form prepuce and frenulum, respectively
The lower portion of labia minora fuses across the midline to form a fold of skin known as a fourchette. It is usually injured during childbirth.
Distance between vulva and labia minora
Both labia minora meet anteriorly
Labia mionra and majora meet
Both labia minora meet posteriorly