We’re both part of the so-called sandwich generation: We’re mothers raising young children, and we also have aging parents and in-laws. President Biden claims he wants to help people like us. His administration, however, has threatened to take away our main source of child care by proposing a regulation that could double the cost of hosting an au pair, a young foreign national brought to the U.S. to work as a nanny.

If Mr. Biden wants to help families like ours balance our home and professional lives, he should expand the program to include senior care—not threaten to destroy it.

American families since the 1980s have taken advantage of the au pair program, run by the State Department. In exchange for providing a young foreigner with lodging, food and a stipend, families receive up to 45 hours a week of child care. More than 20,000 au pairs enter the U.S. annually to work for host families. The program is a win-win: Families receive flexible, in-home child care for about $1,800 a month, which is generally less than the cost of daycare for multiple children or an American nanny. Au pairs, meanwhile, can experience American culture and improve their English.