Local residents like farmer Arturo Gomez are willing to give her the benefit of the doubt.
"This is a town without law," Gomez said. "It is not likely things will change from one day to the next, but let's see what a woman can do ... things can't get any worse."
Drug cartels in many drug-plagued parts of Mexico have killed or threatened police chiefs and their departments, buying off some officers and prompting some others to quit en masse.
In past months, soldiers and then federal police largely took over patrols in the Juarez valley, but they stick mainly to the main road, afraid to venture down unfamiliar dirt roads that are well-traveled by drug traffickers.
"Here, everybody is afraid, and anything that can be done to remove that fear would be good," said Fidel Vega, a 46-year-old gas station employee. "You can see that this girl has a desire to get things done."
But question whether a young inexperienced chief can handle a problem that has stumped even Mexico's federal government: how to cope with the drug cartel threat and underpaid, untrained local police, who are easily corrupted by criminal gangs in Mexico's roughly 2,022 municipal police forces.
President Felipe Calderon has recognized the problem faced by local police forces, whose officers earn average monthly salaries of only 4,000 pesos (about $300). Most of them have completed less than 10 years of schooling and are either at basic education levels or illiterate, according to the report.
In some cities and towns, entire municipal forces have been fired or arrested for allegedly cooperating with drug gangs, and officials say their low wages and poor weaponry -- most use shotguns and pistols, while drug gangs have assault rifles — make them ineffectual or worse.
Calderon has proposed a "unified command" structure in which Mexico's 32 state governments would have state police take on the main responsibility, backed up by federal officers and soldiers where needed.
While the cartels have been more than able to penetrate much tighter security details -- killing mayors and police chiefs throughout northern Mexico -- Valles Garcia says she isn't afraid.
For residents, her personal courage may not be enough.
Amalia Garcia, 58, had to send her five children to live in Ciudad Juarez for their own safety, and now lives in Praxedis with her husband.
"Whoever is here, man or woman, things are not going to change," said Garcia. "Things are bad here and nobody pays any attention."