Daughter of Jesse and Eve (Lybrook) Toney. Phoebe marries George Mullis, 29 Oct 1839, Preble County, Ohio, and they have three children; after his death in 1849, she marries Allen Barker on 28 December 1851 in Fulton County, Ill. Soon after their marriage, a wagon train of immigrants from various States was organized to travel to Texas. Phoebe and Allen Barker decide to start their new life in Texas. On this journey to Texas, Allen Barker was killed by Indians and his scalp was left hanging on a tree limb. This left the wagon train with the young widow Phoebe and her three children by Mullis. Also on this train was widower, Otis Robinson Witham and his five children. Otis Witham had been married three times and these children were by two of them. Widower Witham found he had a lot in common with widow Barker and they married on 28 December 1853, in Illinois while enroute to Texas. Otis' son Walter D. Witham who was born 17 November 1836, died during the Civil War in 1863 while Phoebe's son John Mullis returned from the war. After the Civil War, Otis and Phoebe bought a home and permanently settled in Cleburne, Johnson County, Texas. Here, Otis Witham became a "saddle bag Peacher", preaching from one community to another. Together, they had three daughters, Adie, Alice Malissa and Lucinda. Phebe Toney Mullis Barker Witham died 9 December 1914 at her daughter Addie V. (Witham) Waggoner's home at Price's Chapel.

The Rev. Otis R. Witham and family were charter members of the First Baptist Church organized in Cleburne. Mrs. Phebe Witham was the last charter member of this church to survive. She died at the age of 94.

Phebe was affectionately known as Sister Phebe Witham and was renowned for her knowledge of medicinal herbs and early medicines. Phebe was a well-trained mid-wife and delivered many of the early inhabitants of this county. The B.J. Chambers, Odell, M.M. Crane, Easterwood and many other families used her services.