I followed her recipe made made a batch and used 4 lbs of pw sugar. It tastes delicious. I am having a bit of problem. it is very crumbly and there is no stretch to it. Is there any way to fix it? I don't want to throw it out (tastes too good!!) I post a picture of the fondant :
It's sounds like you put in too much powdered sugar. The recipe says to use 3 1/2 to 4 lbs of powdered sugar. I rarely use the full 4 pounds. Anyway, try kneading small junks with shortening and glycerine. Use very small amounts and then knead. Continue doing this until the consistency is a little soft. After all the small batches are fixed then mix all of the batches together. Wrap the fondant with at least two layers of plastic wrap and allow it to rest over night.
I hope this helps. In the future, try leaving at least two cups of powdered sugar in the bag. More can be kneaded into it before using it.