What happened to Jezebel's body?

Answer: Dogs ate it

Dogs ate Jezebel's flesh, fulfilling Elijah's prophecy.

“So they went back and told Jehu, who replied, “This is the word of the LORD, which He spoke through His servant Elijah the Tishbite: ‘On the plot of ground at Jezreel the dogs will devour the flesh of Jezebel.”— 2 Kings 9:36 (BSB)