I am in the process of going through Family Search sources. There are plenty with children births, marriages, mainly naming Myra Burns as mother. Earliest child, so far, is Harley, b 1892, which would make her 15, IF that is her correct birth year. We have seen gravestone have incorrect years.
I found a birth, marriage of child with Mary Alread and a marriage to Molly Alread, the same person.
All of these sources above say Frank, not Francis. I have not found anything yet that has birth year or age for parents. I have found a few that have F. M. Roll with one of the wives. Mary Allread has the earlier children.
Just found a source that has Francis Marion with spouse of Mary E Ross and Maryette Ross.
I will post all the sources that I find to Francis profile Roll-566