Individual Details

Probably never married. She was with her mother in 1860, her sister Anna in 1870 and 1880.
Although both the daughter and mother were Elizabeth Isaacs, the following record would seem to apply to the daughter, who may have been impaired in some way:
Jackson County Court Records, June term 1874, pg 448:
A rule is made against Ann Jane Harrison and Elizabeth Isaacs to appe ar in this court to show cause why there should not be a committee appoint ed for Elizabeth Isaacs.

In I870, Elizabeth, the sister, was living with Anna Jane, whereas Mr s. Elizabeth Isaacs, the mother, was living with her daughter Rachel.

Birth

Ca 1821

Father	Godfrey S. Isaacs (1775 - 1858)
Mother	Elizabeth "Betsey" Howard (1790 - 1870)
Sibling	John B. Isaacs (1811 - 1894)
Sibling	William Isaacs (1812 - 1860)
Sibling	Rachel Isaacs (1815 - )
Sibling	Sarah "Sally" Isaacs (1816 - )
Sibling	Evaline Isaacs (1817 - 1900)
Sibling	Caroline Isaacs (1818 - )
Sibling	Nancy Isaacs (1819 - )
Sibling	Samuel Isaacs (1820 - 1899)
Sibling	Godfrey Isaacs (1825 - )
Sibling	Elisha Isaacs (1827 - 1904)
Sibling	Rebecca Isaacs (1830 - )
Sibling	Fielding Isaacs (1831 - 1858)
Sibling	Anna Jane Isaacs (1832 - )
Sibling	Henry Stubblefield Isaacs (1835 - 1912)