Its poop. It sounds like your female has consitpation (sp.). You can try feeding it a meaty diet, I hear that helps it out very much. The meat goes through the fish very quick. Also, i have some daphnia that helps the fishs digestive system for situations just like this one.
Some meaty foods is bloodworms, brine shrimp, daphnia. Freezed dried or frozen is fine.
If it was fry then it wouldn't be brown, you would see the fry's head sticking out which you can tell real easy. Mostly transparent with big black eyes.
