It was a big story when the first moon was discovered orbiting an asteroid over twenty years ago. But I have to admit that I was surprised to learn that over two hundred asteroids are listed as having satellites.
Since asteroids are so small that they're difficult to see - unless they come close to Earth like Florence did - that teensy moons aren't going to be easily visible. Apparently, many of the satellites haven't been detected directly, but rely on glitches in the light curve. (Similar to detected of extrasolar planets)
The first confirmed asteroid and moon was
asteroid Ida in 1993. This is a nice clear photo - much better than the radar detection of Florence's moon - because it was taken by the spacecraft Galileo. Galileo did a flyby of Ida while on its way to Jupiter.