When Wang Rong gave birth to her second son, she reminded her husband of a promise he made even before their wedding: to let her pass on her family name.
"My dad had two girls and I didn't want our family line to end with us," the mother from Shanghai told AFP.
"I didn't want my dad to be disappointed for not having a son."
Giving the mother's surname to a child is gaining traction in Chinese cities, defying deeply entrenched family traditions in the country.
The country's one-child rule, which ran from 1979 to 2016, meant daughters have also been tasked with safeguarding their parents' wealth and bloodline - previously this had been the preserve of male heirs.
This caused a shift in some family's attitudes but it was the law change to allow couples to have two children that has ignited the trend for kids to be given the maternal name.
Now, some parents are giving the father's family name to the first born and the mother's to the second child.
Few statistics exist on the issue, but one in 10 babies born in Shanghai in 2018 had their mother's surname, according to the city's population management office.
Others are giving children double-barrelled names using one from each parent.
According to a 2019 study on Chinese names by internet giant Tencent, more than 1.1 million people in China had a combined last name, a tenfold increase from 1990.
"China was under the one-child rule when our first son was born, and my husband insisted on following tradition and giving his name," Wang, an insurance agent, said.
"But I saw my chance when a second child was allowed in 2016."
Her eight-year-old son, He Wenshi, has his dad's surname, while his sibling Wang Yunshi has hers.
The situation has become so common that several of the older boy's classmates have their mother's name.
"He thinks it's normal for his two-year old brother to have a different family name. He doesn't ask why," said Wang.
Shifting power relations
A heated online debate on whether a child should automatically receive their father's family name shook the Chinese internet in March when a woman divorced her husband because he refused to give their child her last name.
"Even if he appears to be a good husband, he still has all the privileges in marriage ... including giving our son his surname," read the woman's post.
It was shared over 47,000 times before it was taken down by censors on Twitter-like Weibo.
The hashtag "#passing on a mum's name" has been viewed over three million times.
In China, women traditionally retain their surname at marriage and the law allows children to be named after the mother or father, but the vast majority of babies get their dad's name.
The new practice signals shifting "power relations" between husbands and wives in China, said Liu Ye, a researcher studying China's gender politics at King's College London.
Women who pass on their family names either earn more than their husbands or come from families with more wealth or powerful social networks, she said.
Often, because of the one-child policy, they have been treated 'like a son' and are more assertive because they have enjoyed equitable access to education and employment opportunities.
This echoes the tradition that existed in China about 2,500 ago during the Zhou dynasty when mothers from powerful clans named their children after them, said Zhang Yiren, a traditional naming expert in Beijing.
Whether a child carries the father's or mother's name has serious consequences for Chinese women, particularly those in rural areas, where men overwhelmingly inherit the family's wealth because they are viewed as heirs who keep the name.
A 2019 survey by the All-China Women's Federation found more than 80 percent of women in villages don't have their names on their families' farmland registration documents, giving them no legal rights to the land.
A centuries-old social preference for boys, because of this belief they continue the family line, has also led to sex-selective abortions causing a national gender imbalance of only 88 girls for every 100 boys in 2018, according to the World Economic Forum's (WEF) Global Gender Gap Report.
In 2014, a county in central Anhui province gave 1,000 yuan in cash ($140) to each family that gave newborns the mothers' surname after the national census found that it had one of the worst sex ratios in China, with 100 girls born for every 172 boys.
Four years into the experiment, this improved to 100 girls for every 114 boys, as families saw that girls could also continue the family line.
But despite the gains in income and education many Chinese women still feel hemmed in by tradition when naming their children.
Often, if a couple's first child is a boy, he will take his father's surname, while the mother is free to give their second child her family name.
But if the first child is a girl and the second is a boy, then there is a real battle on who gets to name the boy, researcher Liu explained, adding that if there's only one child - it's an often insurmountable challenge to pass on the mother's name.
"There are unspoken rules in this game," explained writer Shen Liu, who wanted to give her surname to her only son but gave up after intense pressure from her in-laws.
She added: "This isn't real gender equality. It's just another, albeit quieter, kind of patriarchy. Only this time, it's clad in feminist garb."