YOU SAID:

I like her, but I don't think she likes me back

INTO JAPANESE

私は彼女が好きですが、彼女は私を好きになっていないと思います

BACK INTO ENGLISH

i like her but i don't think she likes me

INTO JAPANESE

私は彼女が好きですが、彼女は私を好きではないと思います

BACK INTO ENGLISH

i like her but i don't think she likes me