If you are unaware of it,and it may hep: I think you can go to
United States records
Oklahoma County Marriages 1891-1959
and find the marriage certificate of:
S.Lee Barnett age 39 and Hellen Smith age 30;handwriting a bit difficult-gives his parents as something like D.G.Barnett and Elizabeth Woolridge. Witnesses were Arthur Smith, and Anna R.Smith--the marriage took place at the home of "Mrs.Smith".
She lives in Longwood Twp. and I think in the 1900 census, she is in that township in Kay Co. with her widowed mother and siblings-mother transcribed as "Massy",but the image looks to be "Marry";among the children are Arthur and Anna.
The marriage record for Hellen gives a birth place of Kansas, but the census shows Illinois,with younger children of the family born in Kansas.