It may be due to fear, and you might need to consider whether that's the best tool for them. Even though the fountain is recommended in many ways, if your cat is really scared of it, then it's not making their life better to have it.
Yes, girls are strong enough to play water polo. They don't have to be super amazing swimmers to play water polo. As long as the know how to swim, they...
Leave a regular bowl available to give your cat some alternative when first introducing the fountain. Start with the fountain turned off so the cat learns to drink from it...