Accommodations are comfortable, if spartan. All rooms are shared. The women help raise some money for themselves by making costume jewelry, and there are plans to have them make and sell baked goods as well. A few items are constantly in short supply -- bedsheets, kitchen equipment, shoes in size 4 and 5. But these women are used to making do with little.
Named for an Indian word for a type of flower, Casa Xochiquetzal (so-she-KET-sahl) is the fruit of an unusual collaboration involving sex workers, feminists, a prominent theater director and the city government.
Munoz says the idea for the residence first took shape when she began noticing numbers of poor, elderly prostitutes in the area around the city's historic center.
"I felt this in my own flesh, and I said, 'Today it's them, tomorrow it could be me who could be in this situation in the street."
Eventually, a friend put her in touch with Jesusa Rodriguez, a theater artist whose El Habito space is known for its feminist-inspired cabaret-style performances.
In Mexico, Rodriguez says, many sex workers enter the trade at a young age and are easily exploited by the organized pimps and madams who run prostitution networks. They also may be prey for police officers, some of whom threaten the women, demanding money or sexual favors, prostitutes say.
"There are many very sad life stories," Munoz says, "and they all are of hunger and necessity, of threat, of kidnapping, of being told that someone was going to kill their children, of fathers, of brothers who brought them to doing sex work and obligated them to do it."
Poor and indigenous women are especially vulnerable to falling into the hands of predators, Rodriguez says. Yet "in many ways," she believes, "these are very creative women. Even with all the difficulties of their lives they still have a very strong sense of life."
In the summer of 2003, Rodriguez met with a group of about 70 prostitutes. The younger women were interested in forming a large, national movement to advocate for sex workers' rights, but the senior women had a more modest goal.
"The older ones, above everything, wanted a place where they could live their life with dignity," Rodriguez recalls.
Two other influential figures joined in at that time: Marta Lamas, one of Mexico's leading feminists and women's rights advocates; and Elena Poniatowska, a prominent journalist and novelist. They helped to arrange a meeting with then-Mayor Andres Manuel Lopez Obrador, who expressed shock that there were grandmothers working as prostitutes a stone's throw from his office.