after your parents were killed the malfoys took you in. they loved you like one of their own, sometimes draco even thought they loved you more. but that wasn't the case, they just felt bad.
you and draco got along very well and he introduced you to some of his friends that's how you became friends with pansy, blaise, mattheo, and lorenzo
you all got your hogwarts letters around the same time.
lorenzo asked you to be his girlfriend in 3rd year, you said yes because you felt bad, he liked you but you didn't like him, you fancied mattheo.
(i forgot to say that you are in 5th year)