Mary Livingston

"Molly married a Livingston and moved to Orange, NJ."

https://www.genealogy.com/forum/surnames/topics/conway/662/

Rebecca Gayle Conway's two oldest children were named in the will of her mother Mary Richbourg Gayle, dated January 28, 1856:

"I give and bequeath to my granddaughter, Mary Conway, a certain negro named Amelia, and should she, Amelia, have issue it is my desire that the first bom go to her sister, Sarah Conway, provided, however, if either or both of the above named grandchildren, namely Mary and Sarah, die without legal issue it is my desire that the above named negro and her issue be divided equally between the surviving full brothers and sisters of the said Mary and Sarah."

Note: the 1860 census suggests that Sarah was the oldest daughter. More information is needed to confirm.

United States Census, 1840

Name: John Conway

Event Type: Census

Event Date: 1840

Event Place: Carroll, Louisiana, United States

Page: 126

1 male 20-30, 2 females under 5 [Mary and Sarah], 1 female 20-30

https://www.familysearch.org/ark:/61903/1:1:XHTD-QQK

Note: next door to Lawrence G. Gale [Gayle], her maternal uncle.

1860 US Census: 4th Ward St Louis, St Louis, Missouri, United States

John Conway Male 53 Ireland

Sarah Conway Female 21 Louisiana

Mary Conway Female 18 Louisiana

Frances Conway Male 17 Louisiana

Michael Conway Male 14 Maryland

https://familysearch.org/ark:/61903/1:1:MHZP-RCR