Yep, that rotten egg smell(Sulfur dioxide I think) is fairly common with ciders during the first part of fermentation. Often means that the yeast didn't have enough nutrients to begin with, but you can also get it with lager yeasts. The yeast will eventually clear it up. IME it's usually gone before 3 weeks, but give her some more time and she will be OK. I probably would have left her on the yeast cake until it cleared up, but what's done is done.