MEXICO CITY — Lois Muñoz, originally from Brooklyn, New York, has been living in her husband Alfredo’s family compound in Puebla, Mexico, for the past three months. Because she has no car and speaks very little Spanish, her world has shrunk dramatically from the busy life she led as a waitress at a diner in Middletown, New York. Muñoz is one of a growing number of Americans who’ve made the move south, choosing to accompany their undocumented spouses who are voluntarily leaving in light of