There's no word in Arabic for girlfriend in a romantic sense as typically there's no such thing as a romantic girlfriend in old Arabic culture. A girl goes from acqiantance to fiance'. There's no in-between.
Ah, on friend صديق I can add ت to mean a female friend صديقت (leaving it as صديق implies male friend), and then after that I can add 'my' ي or 'his' ه or 'her' ها or 'your' ك as suffixes. So we must be very specific.