I encountered her using your save in less than a minute of searching; you're clearly just having bad luck with the RNG.
Weird. I loaded the file in, hoping that maybe does something, but I did three full tours of the Old Forest circuit and encountered pretty much everyone else - hornets, wolves, effigies, demons, elf boy, wyld elf band....and then on the fourth circle, she finally appeared. That must have been some serious bad luck. All in all, I must have done some twenty circles. Now I wish there was a way to disable painted demons, because I seriously can't see them anymore
ETA: Luckily enough, after continuing the above-mentioned quest, it didn't take QUITE as long to run into Viviane again for her to make the new set...