Both women are here to support the same man, 34-year-old Claudio Yanez, one of the 33 trapped miners in Northern Chile. But they barely acknowledge each other, thanks to wounds created many years ago, and have been fighting over who should get Yanez's salary and donations that have come from all over Chile.
"We have barely spoken in six years," said Macias. "And now she thinks the donations and help should go to her? No way."
The miners themselves passed the one-month mark underground on Sunday - apparently longer than any other trapped miners have ever had to endure - and they still face more weeks or months before rescue. The strain also has shaken the fault lines in their families above. Some squabble over who should get the miners' August wage, who should share in the donated food.
The local government has been forced to institute several measures: The miners were asked to send up a note designating who could get their $1,600 salary for August. There are separate bank accounts for each miner, which no family member can touch.
Social workers have been brought in to sort out who gets boxes of food, household cleaners and clothes donated by unions, companies and individuals - helping settle disputes among relatives of about half the families of the trapped men, said Pamela Leiva, the head social worker at the camp of relatives waiting near the mine.
"For each miner, sometimes there are as many as three families to consider," she said. "And to understand them, we have had to dig into the lives of the miners before the accident."
Those lives, just like lives the world over, can be complicated.
There are men who have been living with a partner for years while still formally married to a woman from whom they separated long ago, the result of a rigid divorce law. In a few cases, the legal wife of a miner has come forward looking for donations, said Leiva.
There are brothers and sisters, mothers and fathers on both sides of a miner who don't get along, or who depended on his salary to survive, meaning they can't just wait long months for their loved one to be rescued.
And of course, some miners have skeletons in their unexpectedly opened closets.
Leiva confirmed a story told by other witnesses: One miner's wife and lover were both keeping vigil at the camp. When the two realized they were both praying for the same man, they had a very public argument, and the wife tore down a poster with the miner's photo that the mistress had set up.
The mistress taped her poster back up, and beneath several poems and prayers she had dedicated to him, she added, as if defiantly: "Tu Senora," or "your wife."
Having to designate who gets their salary, a large sum in a country where the minimum wage is roughly $400 a month, can put the men in a difficult situation, and limited communications give them little way to talk through the problems with squabbling relatives 2,300 feet above their heads.
Miner Claudio Yanez designated Cristina Nunez Macias, 26, his partner of 10 years and mother of their two daughters, an 8-year-old and a toddler.
Yanez's mother, Margarita, declined to be interviewed, but his brother, Carlos Yanez, 38, said the tensions had died down the last week, as the two women have had to make peace.
Carlos also said they had come to an agreement on nonperishable items: leave them in Cristina's house until the miner gets out and can decide who gets what.
For all the fissures that have been exposed, the tragedy has also brought families together.
Maria Segovia said that a stepdaughter of her brother, trapped miner Dario Segovia, visited the camp one day and angered Dario's three biological children by telling local media she was his only child. In fact, she was a stepdaughter from Segovia's previous relationship.
But after the blowup came a makeup, and a stronger relationship.
"We love her as one of Dario's children," said Maria.
Despite worldwide attention, the miners' financial future is uncertain when and if they make it out alive.
The owners of the mining company, San Esteban, have said they may not be able to pay wages in September, and are considering bankruptcy.
The day after the men were discovered alive, businessman Leonardo Farkas donated $10,000 to each miner. That money has been put in the miners' accounts, and Farkas has encouraged Chileans to donate.
Money donations are distributed evenly among the 33 miners, said Leiva, the social worker.
While every family is focused on seeing its loved one emerge alive, there is another deep, longer-term worry: Will these men be able to return to work?
Many, psychologically and physically, may be unable to go back in the mines, or refuse to do so.
There are few other opportunities in Northern Chile, and many of the men don't have the education to do anything else that pays as well.
"A big worry is: How they will come out?" said Leiva. "They don't have other jobs."