1850 Hunt Co. TX
Jane Lovel, b. TN, 23
Lavina, b. KY, 2
1860 Buchanan, Atchison, MO
James V. White, b. KY, 35, farmer
Jane, b. TN, 30
S. P., b. KY, 12
1870 Clay, Atchison, MO
James White, b. KY, 45, farmer
Jane, b. TN, 42
Jesse, son, b. MO, 4
Martin G., b. MO, 1
I didn't find Lavina's marriage nor her death in Ancestry and FamilySearch.
They started recording marriage in Atchison County in 1845. However they may have married in another county. The Missouri State Archives has microfiche with marriages 1845-1989.
Some deaths were recorded as early as 1883 but Missouri didn't mandate death records until 1910.
If she died, I don't think you'll find probate records for her because she probably didn't own property or land.
Sometimes local genealogical and historical societies create their own death index and have inventoried cemeteries. You can contact the following:
Atchison County Historical Society
210 South Maint Street
Rock Port 64482
Northwest Missouri Genealogical Society,
PO Box 382
St. Joseph 64502