I believe what you are referring to is GDV (gastric dilatation-volvulus), also know as "bloat". GDV is a life-threatening condition where the stomach literally turns on its axis, causing restriction of blood supply to the stomach and spleen, and if left untreated, can cause death of the stomach tissue due to lack of blood supply and oxygen to its cells. It is much more common in deep chested, large breed dogs, which, as a standard poodle, Charlotte definitely falls into.
Typically with GDV, there are often obvious signs of extreme discomfort, and usually attempts to vomit which are unsuccessful or only produce saliva or foam.
What you can do at this time, is to see if she will take a few of her favorite treats, or a small amount of dog food. If she eats it readily, and keeps it down, it is not possible that her stomach is twisted at this time. If she refuses to eat anything, it is possible that she may be experiencing nausea or other abdominal discomfort, which COULD be the early stages of GDV, or it could be something far less serious. In the case she refuses to eat anything, I would consider getting her checked out tonight just to make sure it is not something serious like GDV that would require emergency intervention. If she does eat something readily, you are probably safe to wait it out and keep an eye on her overnight, then take her in if she still isn't quite right by tomorrow. I hope this has helped! Please let me know if I can be of further assistance :)