Jessy Had To Leave
She orders Jessy to leave immediately! Her arrest would significantly affect her ability to practice law and the cops would show up shortly. Jessy accepts and immediately departs. Even though Mary was able to keep Jessy safe, she still had to make another choice. When given the choice, would Mary enter the basement?
She Took The Opportunity
She makes the choice to take a chance. Given her age and the fact that it was her sister’s home, wouldn’t she be able to come up with an explanation for the police? She enters with a flashlight in hand. And yes, Jessy was accurate in estimating the quantity of photo albums.