That's a beautiful cory! It doesn't look sick. Is it overall larger than the other Trilli's? Females are noticeably larger. Once they are mature, they don't rest flat on surfaces, they are much rounder than the males. To me she doesn't look full of eggs yet though. Right before the females spawn, they almost look like they have a bad case of bloat. This one looks fuller towards the front but not on the sides and toward the back too much.