there. Thanks question. Let me see if I can help.
What type of chew was it? A rawhide type? A greenie?
Do you think she actually chewed it into pieces or swallowed it in large chunks or whole?
Well...without hearing more from you, I can give you my thoughts. If you feel she may have swallowed a large piece than it is possible that it is causing GI discomfort. It should break down over time but sometimes, especially the rawhide or harder type chews will not do so and will obstruct the GI tract. If this is the case, she will continue to show abdominal discomfort and may retch or vomit but not produce much. It would be very important to get her to a vet very soon if you think she might have swallowed a large peice
If you think she chewed it well....then it could be that the type you provided did not "agree" with her. My dog does not tolerate Greenies brand dental chews and will vomit or have diarrhea after eating one (or did until I figured out they were not ). This may be the case with your dog. You can try giving some Pepcid (plain human Pepcid AC/ famotidine). I dont know the weight of your dog but base on general weights of french bulldogs, I would say give 5mg or 1/2 of a 10 mg tablet. If she vomits or can not hold down water or continues with abdominal discomfort, then take her to the vet.
You may want to hold her off of dog food/treats 4-5 hours to see how things progress
I hope this has been helpful. Good luck to you and please remember to rate my response so that I receive credit.