I am so sorry about Bubbles. It might be best to keep the girls apart for a little while, to make sure they don't come down with anything. If you want to put them back together, you will need to make sure that you do have at least two more females. They will also need to be kept apart for a week, to make sure they don't have anything contagious to give to the sorority. Once all the fish are certain to be healthy, you can just put all the females together in one tank. Having 4 means that there is less aggression fixated on a particular fish. If you have room, add more than 4. You can message me any time and I will try to help as soon as I see oyur message.