Shedding?

I got a female betta from Wal-Mart a few days ago because my mother and I are bleeding hearts. I always walk by the bettas and check them out in case a cup is cracked/leaking or someone has thrown two bettas in together or some other emergency that needs help.

Anyway, when we passed by the other night I noticed the female (incorrectly topped with a male lid) was in filthy water, bloated, and had the very early stages of pinceoning. I explained to my mom that she was probably going to die. This incident, being only about a week after we lost a bird we'd had for fifteen years, probably made my mom feel really guilty and she wanted to take the betta home.

I have a tank I could clean out and two other tanks (a two gallon and a half gallon) without filters that I could use in an emergency as med tanks, but I don't really know where I could/should set up the primary take. That said, I didn't think the fish was going to make it, but we both felt awful and my mom said she felt we should at least try to relieve her suffering so we asked the girl in the department about A) changing the water and B) seeing if we could get the fish at a discount on the off-chance we could save her. Well, the girl changed the water but proclaimed, "It looks healthy to me! We don't offer discounts." We got the same answer speaking to someone in costumer service, who said if the fish dies, just bring back the receipt. Real nice.

So I brought her home, put her in the two gallon, soaked her in water with epsom salt, and since this morning the faint pineconing seems to have disappeared and the swelling has mostly gone away. My first thought was wow, maybe she will make it after all. But then I just noticed that it looks like she's shedding? The water looks a little cloudier even though I changed it just last night and I only gave her a few flakes early this morning which I think she ate. (She was really lethargic when I brought her home and not interested in the daphnia or freeze dried bloodworm I tried to give her the day before, but she's perked up since.) At one point she flit around the tank and this piece of stuff came off her side. I was staring at it and looks skin peeling from a sunburn, but if you look close it seems to have the texture of scales instead of skin.

Does anyone know what this is or what it means?