if she is shedding then you wont find a poo, she will wait until she has shed and then poo, quite often at the same time, sometimes its wrapped in the skin, which will be a shame for your first shed.
dont feed until after she ahs shed, she will probably refuse. but even it she doesn't it may cause a big enough lump for the shed to get stuck. and that can cause problems, you can feed as soon as she has shed, she will likely slam it down.