Leaves From My Family Tree

All four children were with Sylvester, and their birth-death dates are as follows:

George Doty (1858-1946)
Abia Frances (1859-1922)
Vesta Hannah (1861-1949)
Charles Ulysses (1864-1867)...was born not too long before Sylvester was drafted into the Union army in the summer of 1864.

Sylvester was with the 11th Iowa Infantry (as you indicated) on Sherman's march to the sea and died of typhoid fever shortly after the capture of Savannah. We have the letters he wrote during the march, and his last one, written Christmas Day 1864, where he reported feeling ill.

Louisa didn't marry Lorenzo Clifford until the 1870's and they had no children together. Lorenzo died in the early 1880's.

Louisa Doty Alden married Lorenzo Clifford on 4 June 1878, in Montour, IA (Tama Co IA GenWeb).

Two years later, the 1880 census lists them with 7 children:
      George Alden, age 22, who would have been Louisa's Son.
      Vesta Alden, age 18, who would have been Louisa's Daughter.
The following five children must have been Lorenzo's children from an earlier marriage:
      Lella M. Clifford, age 11
      Frederich Clifford, age 9
      Minnie J. Clifford, age 7
      Martha J. Clifford, age 5
      Ethel A. Clifford, age 3.