I'm not sure you totally cured the ick. Watch tank mates closely. There is a product called aquarisol I have had good luck with that controls ick and parasites. Not sure it is available to hobbyists. I am a grower in FL. I am not a fan of formaldehide based cures like quick cure as you can burn the fish's gills if you over medicate. Not the case with aquari sol. Ick is not something that is just on the body. It is in the gills and also mouth. Sounds like you got a couple sick fish. Unfortunate. Just watch closely so you do not lose everything. When you buy a female live bearer again...look for one that appears so fat they are ready to pop with a nice dark lower rear. You'll have fry in no time! Goodluck my friend!