Why has she done this to me?

So there's this girl I've known since 6th grade let's say her name is (Sally) Okay so I've heard Sally say 2 times in different classes me being close to her telling her friends that 6th grade was her worst year ever & that she had no friends & no one liked her. But when she was new just a week later since I had also been new, but I had previously gone to that school. Anyway she had a funny way of walking moving her put a lot and pushing it out. So people called her stuck up, but me and my friends invited Sally to sit with us at lunch. But she chose only to talk to one girl let's call her (Mary) well Mary's bestfriend got jealous & they had a fight and what not. And one day when Mary wasn't at school I hung out with Sally at recess and we talked a lot and laughed and were even late to class. So why does Sally say she had no friends and no one liked her? And not too long ago she made up a rumor of me talking bad about my friend when I haven't talked to Sally since middle school.