This brilliantly marked spider is Lactrodectus geometricus, the brown widow spider — a smaller, less “medically significant” sister to the black widow spider, L. mactans. She is not native to Florida — originally from southern Africa or possibly South America, brown widows probably hitched a ride along with traveling humans (or plants, or other cargo) to get to Florida and thus through many states in the U.S. They are pretty widespread in tropical/temperate zones all over the world.
Their color is highly variable, including darker morphs which look a lot more like the black widow, and individual spiders can change color at each molt depending on the substrate on which they live. However, brown widows are generally lighter in color, and smaller, than their more venomous kin, and they usually have both banded legs and a lovely pattern of geometric black, white, and orange stripes on the sides of their abdomen. The brown widow’s hourglass is also more orange-colored than the black widow’s bright red.
Despite the common name, most “widow” spiders rarely actually kill their mates. Brown widows unfortunately haven’t gotten the memo, and the females do, more than occasionally, kill and sometimes eat the males after mating.
Identified by the fine folks at iNaturalist.