Definition of "Sally"

She submitted―for what alternative did she have?―to being Sally in this family, but she always signed herself, Sarah.

1969, Doris Lessing, The Four-Gated City, Bantam Books, published 1970, page 114

Maybe her first name was Sally, but David thought he would have remembered a name like that; there were so few Sallys these days. Now the world belonged to Ambers, Ashleys, and Tiffanys.

2008, Stephen King, Just After Sunset, Simon and Schuster, published 2009, page 8