RoaldoM - she didn't buy it, she won it and is concerned about it.
My kids came home with a fish from a school fair a couple of years ago, it was the saddest scrattiest little thing I'd ever seen, didn't think it would last through the night - it's lovely now, big and healthy and still going strong.
I thought they'd banned it to be honest, we used to always be winning them as kids when the fair came to town - then it seemed to stop for a lot of years, now they've appeared again??
As long as it seems to be swimming and feeding ok I wouldn't think there's much you can do (not that I'm an expert!)