The 1870 census has Harriet Wood was living in the home of her parents (Where were her Yancey children?) and they lived NEXT DOOR to David Lewis . She isn't mentioned in his obituary, but here is a clue:
Deseret News Weekly newspaper: 31 Dec 1873 FHL US/CAN Film _____, item _ Died, Bountiful, 20 Dec 1873, Harriet wife of David LEWIS and daughter of Daniel & Mary WOOD, 38 years 11 months 19 days.

According to Harriet's history:

A widower, David Lewis, petitioned Harriet to be his wife. She told him she did not love him but he would not be deterred. Harriet eventually complied as they were both alone and thought that perhaps through their marriage their lives would be made happier and they were married on 9 January 1871.

Harriet Wood Yancey Brown Lewis died 22 December 1873, one day after her 39th birthday, at Bountiful, Davis County, Utah and was buried in the Lewis plot in the Bountiful City Cemetery.

"In 1864 the family decided to look for a farm where they could raise part of their food. They settled down near Enoch Lewis in Bountiful... On November 25, 1866, a daughter, Elizabeth, the twelfth child of David and Ann, was welcomed into their home. Little Elizabeth was only three months old, however, when her mother Ann died (February 10, 1867). Joshua was sixteen. Mary Ann, who was thirteen, took over the 'mothering' of the five children who were under the age of ten. Enoch Lewis and his wife Jane took little Elizabeth from this time on and raised her as their own. Four years passed before David Lewis married a second wife, Harriet Wood, who was a young widow with one son, Adam. They day David and Harriet were married (January 9, 1871), David first had Ann, his first wife, sealed to him... Harriet, David's second wife, was not to be with the family long, however. On December 22, 1873, she died and was buried in the Lewis plot in the Bountiful City Cemetery. Now the home was without a mother again, but Mary Ann, who was now married, helped out when she could."