Sam wants to know, "Josephine Marcus Earp later wrote a bio with Mabel Earp Cason and Vinnolia Earp Ackerman claiming to be Wyatt's sister.  Who are they?"

Mabel and Vinnolia were sisters.  Neither was Wyatt's sister.  Together they recorded Josephine's memiors in what is known by scholars as the "Cason Manuscript."

Mabel's son Walt describes their place in the Earp family tree in the FAQ "How is Mabel Earp Cason related to the Earp clan?"