I believe the childrens mother was Harvey P. Turner who married Columbus J. McBee/McBay????. They are living with their parents in 1900 Grainger Co., TN Dist 5 and it also looks like they are listed in the home of their grandparents in Dist 1.
Columbus J. McB??--Sep 1873-26-married 8 yrs-TN Harvey P.-wife-Jul 1875-25-m8yrs-mother of 2 with 2 living Robert L.-son-Jul 1891-8 Bettie C.M.-dtr-Jan 1895-5