Thank you for your inquiry, Rebecca.
We welcome any information that the researchers of Kansas can provide.

Silas's mother's name has never been in doubt.
Rebecca Locke even appears on his death certificate.

I checked the 1885 census index by the Harvey County Genealogical Society. I could find on Merriss but I assume Joseph Morris is him. You must have gotten the actual census to find that he was without a wife. I would love to see those and the one of Ramsey that you refer to.

Our records show that Joseph and Rebecca had 4 children. John - 1860, Elmer - 1862, Emily - 1864 & Sarah - 1866 - d. 1868. You state that on the 1875 census, he has a 5 year old living in his household that would have been Rebecca's last born. The child was born in 1870.
Why would the children be left with the father? Maybe Rebecca had a habit of leaving the kids and starting fresh.

We know that she married a Ramsey. So, maybe in the late 1860's she did get a divorce and remarried. You said that from the census records you had S. J. Ramsey, born in Pennsylvania 1844/45. Maybe that is who she married after Joseph.

Could you send me the Merriss and Ramsey census?
We also need to find Rebecca's death certificate,
to help solve this mystery.