If Joe Hayse's reply to your msg is correct and that gedcom I received about 7-8 years ago from a Frank McAlister in NC are any indication, Mary Ann McAlister and John Larkin McAlister were children of Joseph and Eliza Spencer McAlister.
The dates I have for John Larkin McAlister who married Reminah Permina Abernathy (1851-1938) are as follows: b. 18 Jul 1846, Lincoln Co, NC, d. 26 Sep 1921 in Alexis, Gaston Co, NC. I have data on 10 children for this couple.
Additional notes on John Larkin McAlister from the gedcom:
1860. Gaston Co. NC. Chestnut Oak P.O. Age 10. "The 1860 Census ofGaston Co., NC," by Donald Gladden & Linda Bell, page 60.
1880. Lincoln Co. NC Ironton Twp. Age 30. ED 101, Sheet 1, line 49. Birth and death dates taken from "The Hawkins Line," Summer 1985,Vol. 1, No.2, page 2. If birth date is correct, it is probable that John Larkin was the "Unnamed boy, Age 1," listed in the 1850 census as the son of Joseph and Eliza Spencer McAlister.
This is not one of my direct lines (doesn't even come close until prior to the 1740's) so I have not yet verified any of the data from Frank's gedcom. Not even sure I've still got his address, assuming that he is still alive.
But any lead may be the key that unlocks a hidden door in a brick wall. Good luck.