Mary R. Wheeler was born in Ohio to John Wheeler (1781-1833) and Mary Rebecca Baughman (1790-1834), both born in Pennsylvania. Mary Wheeler was the sister of Sarah Wheeler, who married James Lance.

Mary's first husband was David Richards, who was born about 1824, in Ohio. In August 29, 1850 Census for Chippewa Township, Wayne County, Ohio, they are a young married couple [David, age 26 and Mary, age 21]; with no children, living with Jacob Shaffer, age 75.
David Richards was the half-brother of James Lance, the son of Abram Lance and Mary “Polly” McCormick. James Lance was also the husband of Sarah Wheeler (Mary Wheeler's sister).
In 1854, David and Mary Richards, along with his half-brother, James Lance and Mary's sister, Sarah Wheeler Lance left Ohio to try an make a home in Michigan. David Richards died sometime between 1863 and 1870.
******Their nine known children were:

Mary R. (born ~1851)
Abram Richards
Marilla (born ~1855)
William Henry Richards
Sarah Richards Moeller
Isabella Richards Thuma
Addie I Richards Lee
James Richards
David RIchards

Mary's second husband was Abram Lance, Jr., who was born in 1826, in Medina County, Ohio. Abram's father was Abram Lance, Sr. and his mother was Elizabeth Halliwill, who died a few months after his birth.
Abram Lance, Jr. was the half-brother of James Lance, who was married to Mary's sister, Sarah Wheeler.
******The five know offspring of Mary and Abram Lance were:

John Lance (born Feb. 1865, died after the 1920 Census)
Mary "Elizabeth" Lance Herman
Frank Lance
Frances Lance Young
R B Lance

According to the 1910 Census, Mary Lance was 82 years old and had given birth to 15 children and 9 of those were still alive, at the time of the census.
Her 9 children, who were alive in 1910 were:
Abram, William H., Sarah, Isabella and Addie Richards;
and John, Mary Elizabeth, Frank, and Frances Lance.
[Mary had 9 known children with David Richards and 5 known children with Abram Lance, for a total of 14 children; so the name of one of her children is unknown in this FindaGrave memorial for her.]