Need advice with a brick wall for one of my 3rd Great-Grandmothers, Sarah Lucas

I'm looking for some advice in determining where to look next for any information about one of my 3rd great-grandmothers, a brick wall.

Her name is Sarah Lucas, born in 1845, somewhere in Ohio. The source, indicating the year of her birth and the state, was the 1870 census. For Harrison Township, Blackford County, Indiana, she is listed on page 33 as Sarah Havens (well, it reads Heavens, but it's Havens). Her daughter, Bertha, listed there as a child of 2 years, is my 2nd great-grandmother; I'm as close to 100% certain as one can ever be about genealogy that this is a valid record of my 3rd great-grandmother, 3rd great-grandfather, and 2nd great-grandmother as a 2-year-old child.

She married my 3rd great-grandfather, Benjamin Franklin Havens, on 25 Jan 1866. I found those records as well, indicating her birth in Ohio.

As a next step, I did an Ancestry census records search for a Sarah Lucas, in Ohio, born on or about 1845. I came up with several possibilities, but only one really stood out as being likely. From the 1850 census, a Lucas family, with a father named James and a mother named Sarah, and a daughter also named Sarah (along with other siblings), out of Strongsville, Cuyahoga, Ohio. I found the same family in the 1860 census (with the same parents and children), now living in Scott Township, Kosciusko, Indiana. This seems a very likely candidate. The other "Sarah Lucas" records in Ohio didn't appear in Indiana census data, and I found them in later Ohio census data.

That said, there is no clear evidence that the Sarah Lucas from the census data is the same Sarah Lucas who is my 3rd great-grandmother. I've not been able to source any other records that would indicate that those two records - the marriage record and the census record - are one and the same person.

I attempted to use DNA matches to help with this. My father also has a DNA test done; he's closer genetically than I am, so his DNA record is better for finding those details. But that has proved to be very difficult to sort out and make any sense of. There doesn't seem to be any clear way to determine those matches either.

I've found other records on FamilySearch using the full-text search, but nothing that links the Sarah Lucas who married Benjamin Frankly Havens to the Sarah Lucas who moved from Ohio to Indiana with her parents. Perhaps they are the same, but I would like more evidence to support that.

Any suggestions on where to look or what to look for in making a connection or link?