YOU SAID:
My crush has a girlfriend
INTO JAPANESE
私の片思いにはガールフレンドがいます
BACK INTO ENGLISH
I have a girlfriend in my unrequited love
INTO JAPANESE
片思いの彼女がいる
BACK INTO ENGLISH
I have a girlfriend who has a crush
INTO JAPANESE
私には片思いのガールフレンドがいます
BACK INTO ENGLISH
I have a girlfriend who has a crush
That didn't even make that much sense in English.