Seems unlikely! Is it possible that she is relieving herself in the house, somewhere you have not noticed? Check for a wet whiddler, ever couple of hours, to see! One of my monsters dos that on rain days. "no Mom, I'm fine, maybe later...
" But on closer inspection...
... the deed was done! lol
If she IS holding that long, I would be getting a vet check.
About an hour per month of age, up to 7-8 hrs is good holding power! IMO