These are lithographs published in the 1950s for sponsors of an annual art event in New York city, I think it was for Artists Equity. The prints are for sale on Ebay.
Website showing her works.
Marilyn Pink Fine Art result.
National Portrait Gallery UK.
Another blog link
1950 Original Lithograph Clara Klinghoffer Artists Equity Association Nude Women - Original Lithograph
Other Amazon results for Clara Klinghoffer