My guess is the snake will poop when she sheds. Very common and nothing to worry about. It will most likely be next to a rolled up shed skin. If not, as long as the vent area sheds properly she will probably poop soon after the shed.
One question though, what is the weight of the snake and what size prey is being fed? If the snake is being underfed it will use almost the entire prey item for growth and will not have any left to poop out.
...but, that being said, I'm guessing that's not the case and she will poop when she sheds.