Individual Details

Marinda had the middle initial "B" in 1850, but I suspect this should have been an "E" and her middle name was Elizabeth:

By 1860, Todd Co KY, Elizabeth Poindexter age 16 [who must surely be Marinda "B" from 1850] and Lawson Poindexter, age 10, were living with Wells Fowler, a silversmith who was age 70 and E. Fowler, age 48. Elizabeth & Lawson were both listed as born "TN" as was E. Fowler - they were simply dittoed from her place of birth. The Fowlers were not in the 1850 census in Todd Co.

By 1870, Elizabeth Murphy was again going by the name of Elizabeth Poindexter.
1870, Todd Co KY, Trenton Precinct:
Elizabeth Poindexter, age 58, b. TN. Maranda "B" age 26, b. KY, Richard H [? name hard to read] age 4, and William L. age 20.
My note: I would think the 4-year-old belongs to Maranda - her mother is too old and he was listed following her name - only the head of household had a surname written.

1880, Todd Co KY, Trenton Precinct:
Lawson Poindexter, age 29, b. KY, parents b. VA; Henrie, age 24, wife, b. KY, parents b. VA
Mamie, age 5; Etta age 3, Ned age 1, and Dicke, age 13, a nephew [presumably Richard H. the 4-year-old in 1870]

Birth

1843

Kentucky

Father	John C. Poindexter (1799 - )
Mother	Elizabeth Murphy (1813 - )
Sibling	Mary P. Poindexter (1834 - 1835)
Sibling	Dolphin B. Poindexter (1835 - 1841)
Sibling	Marian W. Poindexter (1841 - )
Sibling	Lucy Ann Poindexter (1846 - 1847)
Sibling	William Lawson Poindexter (1850 - 1918)