I have a question about William Howard Taft's family.?

Taft's daughter, Helen, married a college professor, Frederick J. Manning and they had two daughters, Helen Taft Manning (born 1921) and Caroline Manning (born 1925). Helen married and became a Hunter and Caroline became a Cunningham at her marriage. Are either of these two granddaughter's of Taft's alive still. Also, does he have any other living grandchildren?