enm .as a girl ,i want to tell you that not a girl will take the words“ i love you" as a joke ,she will take it seriously,and love is for two people,if you have the feeling that you love her, i am sure she can also feel it ,you are a great man ,tell it brave and you will know the result,maybe the only thing you lack is the confidence, then not hesitate!tell her !and i am sure you will win her heart!