The first revolvers–and the ones we are more used to seeing had fixed cylinders. That means you had to push out each spent cartridge individually, reload, then move on to the next one. Or the entire cylinder was removed and replaced with one that was pre-loaded.
The more modern revolvers use a swing-out cylinder, meaning the entire cylinder pivots out of the gun for easy reloading.
Between those two types came the Break Top or Top Break revolvers. Smith and Wesson came out with their Model 3 American in 1870, but most gun manufacturers manufactured a version of the weapon in the later half of the 1800s.
In the first break top revolvers, the barrel and cylinder was hinged on top. That meant turning the gun over, “breaking” it open, removing the spent cartridges, reloading, then returning it to a firing position. Definitely not a quick loading weapon.
In the next generation of top-break revolvers, the frame was hinged at the bottom front of the cylinder. All you had to do was release the lock and push the barrel down to expose the cylinder. At the same time, on most models, dropping the barrel operated an extractor which pushed the spent cartridges out far enough that they fell free, or could be easily dumped from the cylinder. This type of break tops could be reloaded one-handed, without releasing your firing grip. Though they were still small weapons with limited range, being able to reload faster meant it was a better gun for defense.
The Break Tops were also made to use .44 and .45 caliber cartridges, so they packed a punch. Probably enough to set your heroine back on her boot heels.