How do I dodge Melenia's waterfowl dance?
I'm sorry, but I don't understand what you mean by Melenia's waterfowl dance. Can you provide more context or clarify your question?
Melania is a character from the video game Elden Ring, do you have any information on this?
You can try hitting her with a Freezing Pot. Throw the Freezing Pot when she's floating in mid-air, just before she strikes.  It should disrupt the Waterfowl Dance and return her to the ground, where she'll take freezing damage.