"Kız arkadaşını" make me think to a girlfriend.
I would translate "amiga" as "arkadaşını" and put in the comment field an explanation that "amiga" is used for a girl.
hi, dear miss! hope you're fine!
thanks for your comment!
In my opinion this translation is ok, becouse if 'amiga' is used for girl, then it should be 'kız arkadaş' in turkish. Maybe I should explane, that 'kız arkadaş' is not used always as 'girlfriend/lover', it could be just a friend.
hugs