Im thinking aggression more than anything. With Brook, at the onset, fish may scrape up against objects, rapid respiration develops, and fish often gasp for air at the surface as the gills become clogged with mucus. Very quickly the fish will become lethargic, refuse to eat, and its colors will fade. The most noticeable symptom of Brooklynella is the heavy amount of slime that is produced by a fish that has contracted this parasite. As the disease progresses, a thick whitish mucus covers the body. This will usually start at the head and spread outward across the entire body. Skin lesions appear and it is not uncommon for signs of secondary bacterial infections.
In your case and as pointed out by Jay H , female clownfish are much more dominant than their male counterparts. They greedily try to eat most of the food that gets into the tank (which is one reason the males don't grow as large). They will often aggressively protect their "home", whether that be an anenome, a nesting site, a clay pot or the entire fish tank.