It's not too late.
China is lucky in that they border a country with the opposite problem [1]:
> One feature of the Russian-Chinese relationship seemed especially telling: Cross-border marriages are overwhelmingly between Chinese men and Russian women. Much of this has to do with demographics—Russia has a surplus of women, while China has too many men.
In addition, the demographics issue might be overstated as many of the 'missing women' started to be 'found' once they turned 18 and needed to officially register with the government [2]:
> The researchers believe local government officials informally worked with farmers and acknowledged that they couldn't fully enforce the one-child policy. Instead they made tacit agreements in allowing families to have extra children in exchange for social stability in their communities. The cadres, or local governments, would then under-report “out of plan” births that ultimately influenced the national population statistics.
> To supplement the qualitative data, the researchers then examined Chinese population data by cohort, and they compared the number of children born in 1990 with the number of 20-year-old Chinese men and women in 2010. In that cohort, they discovered 4 million additional people, and of those there were approximately 1 million more women than men.
> "If we go over a course of 25 years, it's possible there are about 25 million women in the statistics that weren't there at birth," Kennedy said.
1. http://www.slate.com/articles/news_and_politics/dispatches/f...
2. https://news.ku.edu/2016/11/22/study-finds-chinas-missing-gi...