Wow, there's a spate of kitties peeing on beds in the past couple of days! One of mine was doing this recently too.
Have you been to the vet recently? It seems like she's not able to hold her pee. I know that for others who've had this problem, it turned out that kitty had a UTI.
My cat had no health issues as far as the vet could tell. I just have to keep my bedroom door closed to make sure she's not tempted - she will also poop on the bed when she's constipated.
Do you have any other kitties? Is she stressed, maybe?
One suggestion is that you use Nature's Miracle to clean up, to make sure that the pheromones are gone. Otherwise, she'll be attracted to the same spot. If she's been peeing in other places, you'd probably know pretty quickly from the odor.