If he does have Mareks, and you don't know that yet, sometimes they can have a transient paralysis, that can go away, then later develop other symptoms such as lymphomas or tumor. I'm not an expert on Mareks--many others on here know much much more.
I was just wondering about the possibility of botulism. Could she have gotten into anything that has rotted, like an animal or fish carcass, rotting vegetation from a compost bed, or maggots? Botulism is a toxin that can cause leg paralysis, then it climbs upward in the body affecting wings...
Dawg53 has a good post somewhere about the method for getting tapeworm, but it is for Valbazen, not SafeGuard. For tapes you need to use a larger dose than usual. Normally you would give a pea-sized amount (or 1/2 ml) of SafeGuard, but I would give 2 or 3 times that, for 3 days in a row. Than...
Dawg53 is the best worm expert on BYC. Valbazen is the only wormer that will for sure get tapeworms. You might want to have your vet check a stool sample for sure. It is harder to treat tapes than other worms. SafeGuard horse paste or liquid goat wormer can also be used at larger doses...
I would second not bathing in this kind of weather. You can turn her over, part the feathers, and can see lice or mites crawling if she has them. Sevin dust will kill either lice or mites immediately, and retreat in 7-10 days for the lice /mite eggs. On her vent if those little white specks...