If we are talking about the same Phebe Eilizabeth Potter, her mother was Mary Smith and her father was Philip Potter.
Mary Smith Potter Bartlett lived and died in Danby, Rutland, Vt.Phebe's sister Lydia also stayed in Danby, VT.If she was writing letters I would assume it was to these 2 women.Can you confirm this connection trough the letters?
According to my research, Phebe was born in Granville, Washington, Ny.The family lived there until the death of Philip Potter in 1835.
According to familysearch.org she married Thomas Harbison Kenley in 1834 in Mississippi.I do not know why the family moved to Texas.Families often moved around quite a bit in those days. Possible reasons were land grants from the government or cheap land.
If you believe that this is your Phebe that would mean we are cousins.I have a ton of information on her family line.Let me know what you think.