There is no way a villa owner would allow renters to bring their pets, correct? Maybe one dog or a caged ferrit? I know it's asking a lot but it's worth a try :). It's not me, we have fish! Asking for a friend of mine.
There are a very small number of owners who have "Pet friendly" homes. They do allow pets, and generally charge an extra cleaning fee and ask for a much bigger security deposit. These homes identify themselves as being Pet Friendly because they have to ensure that they don't then rent to people who have allergies to animals.
Ask your friend to send an enquiry on all 3 sites and if there are any "Pet Friendly" homes available for her dates then I am sure that the owners will contact her. Also ask her to make it a General Enquiry, so that she widens the chance of finding a home, of any size, that does take pets.