id wait to see if the other females fry are alright the males dont tend to be a big problem in my experience its mostly rival females and stressed mamas. what kind of plant or other separation do you have? its best if they cant really see each other and caves at opposite corners of the aquarium. technically IMO for a trio to be easy i wont say possible you need a bigger tank foot size like 40breeders are perfect, just 20 highs keep them close together where they run into each other a lot but the corydoras are fine they make it so they pull their aggression away from each other.