Callie was living with her father in Estill County in 1930 too. Here is the record.http://interactive.ancestry.com/6224/4584826_00916/82235437?...
She was listed as widowed.
Just to give you a "heads up", "widowed" does not always mean "widowed." Sometimes it means divorced, separated, or "he's just gone."
There was much more shame in divorce then, so women didn't always admit it to the census taker.
Ben's exact birth date was 22 September 1891, as shown on his WWI Draft Registration.
PS. I just found your family tree online. Your profile says you live in Georgetown. Have you been to the courthouse to look for divorces, estate settlements, etc. Any lawsuits? Ben was a farmer. Did he own his farm? If so, what happened to it? Does the library have the Scott County newspapers from this period? Is there an index?
Since Callie had children born in 1919 and 1921, but none later. It looks like Ben was dead or gone by about 1922/4. This narrows the gap you have to look at.