Lois

From the experts:

The eternal fiancee of Superman turned sweet gray-haired lady who's always available to babysit her grandkids. Lois is actually a New Testament name of Greek origin: she was converted by Paul and was the grandmother of Timothy, who became one of Paul's disciples. Other s-ending names are making a comeback, as is Louise, so why not Lois?

Lois was a Top 20 name in the 1920s and stayed in the Top 50 into the 1940's, but dropped off the list completely in 1983.