You were a normal pick pocketing, 16 year old but one day you ate a diamond but not just any diamond Bertineli fortune diamond and Roman Sionis sent Harley and the half of Gotham's assassins after you with a million dollar reward, without Harley even knowing

After getting you and robbing a store then taking you to her place on Docs restaurant hiding from Roman and other assassins, she actually seemed to like you, like you were her partner in crime, even if you two just met

you were growing on her