What is the ruling regarding moisture exiting the vagina after waking up from sleep, without recalling a wet dream (احتلام), and is it considered maniyy (seminal fluid) necessitating ghusl (ritual bath), knowing that I am aware of the characteristics of maniyy but am referring to a small quantity?

If you wake up from sleep and find moisture, and you do not recall a wet dream, and you are unsure if it is semen, then ghusl (definition) (ritual bath) is obligatory upon you, even if the moisture is little. It is not a condition for the discharge to reach the underwear; rather, if it reaches the apparent part of the body, it has its rulings.