She is definately female! But that isnt to say you dont have two females....
I had a pair together for nearly 2 years! They spawned every other month but eggs were never viable, always assumed it was water quality/my fault... until one day i actually witnessed the spawning and saw one lay the eggs and as i thought the second (male) was fertilising them.... i noticed that it followed behind the female......... and also lay eggs! Eggswere identical, i'd not have known if i hadnt seen it! And the second whom i thought male was a a different build to the first, longer fins and nuchal hump of sorts too!!
I had two females that were very much bonded and spawned together. Always possible! had a bonded pair of male angels too lol
I did the same thing with the other Discus on another forum and got 9-0 votes on female. Unfortunately, it seems that they're an incompatible pair too bad...