Rebecca Jae Sisko was the daughter of Benjamin Sisko and Kasidy Yates. She was born in September of 2376 in the Ashalla monastery where her mother had been held hostage by parasite infected Bajoran monks. (DS9 novel: Unity)

She was named Rebecca for Benjamin's (non-biological) mother and Jae for Kasidy's mother. Other names considered by Kasidy included Rachel Jadzia, Curzon Tye, Sylvan Jay and Joseph Cusak. (DS9 novels: Unity, Avatar)

She was raised at her parent's home in the Kendra Valley of Bajor. (DS9 - Worlds of Deep Space Nine novel: Bajor: Fragments and Omens)

Her birth fulfilled Ohalu's prophecy of the Avatar of Peace.^{[citation needed]}

In 2380, Rebecca was kidnapped due to her being considered the Avatar of Peace and was nearly killed. In 2381, Sisko was forced to leave Kasidy and Rebecca, due to the deaths of several people close to him, which Sisko saw as warnings from the Prophets coming true. (ST - Typhon Pact novel: Rough Beasts of Empire)