Self esteem issue....she needs help...shes crazy!!!?

so i have a friend named alleighah and she thinks guys dont like her alot. but the thing is they stare at her and flirt with her and one guy asked to do her and he was like 20 n shes only 14 and this other guy told her stepmom she was beautiful and these 2 guys we met at the pool said she was really pretty. i think shes pretty but she doesnt believe me....what can i do to make her believe me cause it really bothers her and she thinks shes ugly.