A recent study by Robin Lumsdaine, visiting professor at Erasmus School of Economics and the econometrics-alumni Stephanie Vermeer (which appeared in the journal Demography in April 2015), has been covered in a Harvard Business Review article.
Robin Lumsdaine and Stephanie Vermeer analyzed longitudinal data from over 47,000 women and found that the arrival of a grandchild, holding all other factors constant, raises by 8.5% the likelihood that this woman will retire. That impact increases 1.5% with each additional grandchild. Of women 58-61 years old, the percent working full time was 43% for those with no grandchildren, 37% for grandmothers not caring for kids, and 29% for those who were caring for children.
Karen Firestone, author of the Harvard Business Review article, is the President and CEO of Aureus Asset Management. Firestone became a grandmother at the age of fifty five, which is relatively young for an American professional woman. She had four children by the age of 30.