Contact or google the James Family Farm in Kearney, Missouri. I have seen thethis group photo along with the picture of Zerelda. Eric James has att. to the site called "Fallen Leaves" He my be able to help you identify the people in these pictures.
There is also a Jesse James museum(?) in Wichita, Kansas that may be able to help as well.

FYI I do have Facial ID software.