The Historical Society I mentioned is the Oklahoma Genealogical Society Library in Okalhoma City.It is referred to nowas the State History Center.They have most of the newspapers from all over the state on Microfilm there.I have been reading the Healdton Newspaper, the Cornish/Ringling newspaper, the Wilson newspaper and the Ardmore newspaper for some projects that I am working on.
If your person died in 1903 it is going to be hit or miss if you find anything on them.From my experience reading the Healdton newspaper for my research, and if memory serves me right, the Healdton papers started around 1913/14.Cornish had a newspaper way earlier.While Cornish was in Jefferson county about 5 miles from Healdton, it carried Healdton news.
I would suggest you might want to contact the Wilson Museum (you can find them on line).They have obit books mainly for Wilson, but have them for other areas of Carter County also.
Have you checked the CArter County cemetaries on line.I saw a Jennie Sexton buried in the Mt. Olive cemeteary, and she died in 1905.
Generally, when one speaks of townships,it is in regard to townships from census records.I know they have 1900 census records for some of OK and In Territory, but if it is the area you want, I couldn't say.
I would suggest you make a trip to OKC and spend the day researching in the History Center.It is much easier to do research there now that they are in the new building.