I have the same info as you have. The problem is her last name being Vernon. Nothing matches up. My feeling is that she was either taken in or adopted by Thomas and Isabell. There were several families that seem to have traveled to the Lebanon Missouri area together and I believe the Vernon's were a part of that group. Birth certificates for that time in Missouri are almost impossible to find since there was no statewide requirement until 1909 If you are close to Lebanon, it might be best to go there. There is a genealogical society there but the have not responded to any of my inquiry's.