The ugly duckling

Calli has never felt beautiful because she was always being compared to her older sisters who were much prettier than she is and also any of her boyfriends dumped her for a girl that was prettier than her so she was always concidered an ugly duckling. So after highschool she dicided to move to london to start a new better life to make sure of that she said she wouldnt let herself fall for a guy until she was sure he wouldnt leave her. But when she meets niall horan and he falls in love with her will she belive him or be too heart broken from the past to let him into her life?