NEW YORK — When ­Michele Fitzgerald and her daughter, Jenni, go out for dinner, Jenni pays. When they get haircuts, Jenni pays. When they buy groceries, Jenni pays.

It has been six years since Fitzgerald — broke, unemployed, and in default on the $18,000 in loans she took out for Jenni’s college education — became a boomerang mom, moving into her daughter’s town house apartment in Hingham, Mass. Jenni pays the rent.