But unlike most hairdressers, she doesn't charge her customers. Instead, she pays them.
The country is a major source of human hair, feeding the global demand for wigs, weaves and hair extensions.
"Myanmar hair is the softest, most sought-after hair in Asia," said Aye Aye Thein, whose hair stall is nestled between those of a greengrocer and a betel nut seller.
Figures suggest the global trade in human hair was worth $87.4 million in 2016,
with Myanmar the third largest exporter after India and Tunisia.
In Myanmar, hair can be considered sacred: The gilded Shwedagon Pagoda, one of the Buddhist country's holiest sites, is believed to be built on strands of Buddha's hair.
But it's also common for women here to cut their hair to make ends meet and during Buddhist New Year celebrations, when some women and girls become nuns for a short time and cutting off their hair shows an absolute sacrifice, a detachment from any distractions.
Much of this hair makes its way to China, where it's processed and sold to hairstylists in the West. But as Myanmar grows richer, opening up after decades of military rule, there are fears that fewer women are willing to part with their locks.
On an average day, Aye Aye Thein says, she has seven to 10 customers.
"Look at this hair! It's really nice," she said, gesturing at one thick clasp of hair in her palm. "It's not oily, not too dry, small bits aren't breaking off, light and fluffy."
She then gestured to the tops: "It should be solid, no frizz or split ends."
The pricing of hair depends on the quality and weight, which is weighed in "viss," a traditional Burmese unit of measurement, roughly equal to 1½ kilograms.
Huddled over a battered pair of scales, Aye Aye Thein estimates the price of hair by its feel and a simple scrape of the bundle with an open scissor arm to test for firmness and smoothness.
Placing the hair on the scales, she then measures it in viss with small weights before handing over a wad of money to a customer.
Most transactions range from 15,000 kyat ($11) to over 200,000 kyat ($150) for hair over 10 inches. This income goes a long way in Myanmar, where the minimum wage is 3,600 kyat ($2.70) a day. The hair that fetches the highest price is usually from women with ankle-length hair whose locks can be divided into many bundles to be sold individually.
Men occasionally grow their hair to sell it but it's not common -- although buyers don't discriminate between male and female hair.