Ylla is a character from "The Martian Chronicles", a collection of stories by R. Bradbury from 1950. This is one of my favourite books, hauntingly beautiful and immensely sad. And SO relevant.
In one of the stories, Ylla is a Martian woman who, unhappy in her marriage and longing for romance, connects against all odds with one of the first Mars explorers from Earth, Captain Nathanial York. Her very thoughts, however, prove to be his death. So ends Earth's first expedition to Mars.