I also found a record for Eliza Posey of Opelousas, born 1815. Entered school Feb 7, 1824, and left Oct 26, 1830
(GC: ASHA: Student register # 19)
William Offut married Eliza Posey Jan 25, 1834. Opelousas Court house marriage # 14
William Johnson Offutt widow is Eliza Marie Posey. Will & Estate dated April 18, 1843. (LSAR: Opelousas; 1843)
Eliza Posey M. married to William Offutt, succ. dated April 25, 1861. Opelousas Court house Succ # 2433)
There's additional information on the Posey family if you'd like it, just let me know.