I tried to give her a pill stuffed rat on Sunday, but she wasn't interested because she is in shed. Hopefully next week she will take the rat, if not I will go back to vet and hope they have the injectable meds in stock. There are only 2 ways snakes can get tapeworms: insects and rodents. I don't think tapeworms are species specific either, but the only way to get them really is to eat the eggs.
I will check with my vet to see if he knows anything about this, but I do know that rats/mice need to be frozen to a certain temp to kill the parasites. I don't know what that temp is though.