Hong Kong(CNN) Thirteen and just married, Jie looks at her wedding picture framed in white. Next to it, incongruously, are stickers from the Pixar movie "Cars."
Jie married her 16-year-old husband three days after they met during the Lunar New Year in 2014. Not long after, she was pregnant.
It sounds like a scene from China's feudal past, when early marriage was customary, especially for girls, but teenage brides and grooms aren't uncommon in some poor and rural parts of the country's hinterland.
The reasons are complex -- as economic pressures, shifting social attitudes and changing population dynamics revive a practice that China's Communist leaders had hoped to stamp out.
Photographer Muyi Xiao met Jie and her husband Wen in the southwestern province of Yunnan in 2014.
Jie was the youngest of a number of young Chinese newlyweds she profiled in a tender and fascinating series of images that helped earn 24-year-old Xiao a prestigious photography fellowship with the Magnum Foundation.
"Every girl I saw in these villages got married before they were 18 and some of them were extremely young," says Xiao.
"It's like something they think is normal to do -- it comes from the teachers, from the parents, from the kids."
Xiao, who traveled in the region for 18 days, said the marriages didn't appear to be the result of parental pressure, nor a kneejerk response to an unexpected pregnancy.
"I didn't see any forced marriage. The kids are happy, they say they fell in love."
She said the teenagers she profiled weren't comfortable giving their full names.
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In China, the legal age for marriage is 22 for men and 20 for women but there's no specific penalty for breaching the law, according to Jiang Quanbao, a professor from Xi'an Jiaotong University.
He says in rural areas many recognize a marriage as long as a couple holds a ceremony and banquet; official registration would take place once the couple were of age.
As such, he says it's difficult to tell how widespread early marriage is. Official figures suggest that the average marriage age is rising -- 26 for men and 24 for women.
But tales of young love have been ringing alarm bells.
In February, pictures of a wedding held for two 16-year-old went viral on social networks and received widespread coverage in state media as debate raged over whether they could really be in love.
The couple told a local newspaper that they had the full support of their families, who paid for the banquet.
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Many rural parents are keen for their children to tie the knot before they go off to work in factory towns -- a common fate for many -- and this is especially true for sons who may face a struggle to find a partner, says Jiang, the professor.
The one-child policy and a traditional preference for sons has caused a massive gender imbalance in the Chinese countryside -- latest figures suggest that there are 33.6 million more men than women in China.
These men are often described as "bare branches."
"In some poor areas, getting married early is like a guarantee so they can avoid being bachelors forever," said Jiang.
Xiao blames a lack of sex education and that many children in villages grow up without the supervision of one or both their parents -- part of China's "left behind" generation whose parents go off to work in factory towns and richer cities.
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"They watch a lot of romantic dramas but they don't have much sex education. No one told them that having sex isn't the right thing to do."
But Xiao's warm-hearted images don't pass judgment. They show couples that, for the moment at least, look very much in love.