Fragrant Honey, Ashes and Frost was a TV series. The plot had nothing to do with biological knowledge. Egrets are birds, but dragons are animals. They're not the same species. Jinmi and Phoenix were characters in Xianxia novels. Their fates and emotions were created by the author. In real life, there was no reproductive isolation between humans and animals, so it was impossible for Jin Mi and the phoenix to give birth to a dragon.