Roxanna is the widow of James Dewaine Davis, who died in Pottawattamie County, Iowa on 1 August 1847. She came to Utah with two of her children Charlotte and Philetus. On 20 May 1849 "Roxany" Green (she had married Ephraim Green) was re-baptized at Salt Lake City and received a Patriarchal Blessing on the same day. These ordinances took place prior to the arrival of the 1849 emigration, which confirms that the family came to Utah in 1848.
In the 1850 federal census of Utah, Ephraim Green, "Roxana" Green, Charlotte Green and Philetus Davis are all in the same household but in the 1860 census "Roxana" and Philetus are back to using the surname Davis even though they are still in the Ephraim Green household. They were living in the Salt Lake 17th Ward. In the 1880 census "Roxani" is living in Bountiful, Utah with her daughter and son-in-law; this is where she is buried.
Additional research is needed to identify the name of the pioneer company with which the Davis family crossed the plains.