Clara/Carrie appears to have died before 1910. Her daughter, Christina, is found in the 1910 Fredericksburg, Virginia census, living with A H Boggs and his sister Bettie L Boggs. They have numerous children in their care, “Schullan(s)”, their occupation/industry is a “Charity School”.

Robert, Father-in-law, is found living with his daughter, Mary Agnes Curtis and her husband, Calvin H Curtis, in the 1910 Fredericksburg census.

I haven’t found Robert and Carrie’s daughter, Elizabeth, age 6/12, after the 1900 census.