When Fu Ping was removed from her Shanghai family and sent back to Nanjing, her story involves two groups of Red Guards, one in Shanghai and one in Nanjing.
The Shanghai group consists "four boys and a girl." They used minor force to take Fu Ping out of her Shanghai family, revealing her family secret and denying her a last hug with her mother in the process, and threw her, literally onto a train through a window, alone.
The Nanjing group only has two people, one boy and one girl. They picked her up from the train by calling her name and took her into the city.
How did this sophisticated operation work? Fu Ping did not know. So she speculated on Page 24 in Bend, Not Break:
How did they [the Nanjing group] known where to find me? Bent Star [one of the Shanghai group] must have notified them that I was in car number five.
But that is just impossible, for a couple of reasons.
Red Guards first appeared in Beijing at the end of May, 1966, in Beijing and quickly developed into a national frenzy by August that year. Nonetheless, the Red Guard at that time was not (yet) a centralized organization. It is essentially a vast collection of local groups or gangs of extremely activist teenagers. With free travel during the "big linkup" (大串联) period that year, groups in different locations did make contact with each other, but only at a superficial level.
There have been no records, either in historical archives or personal recollections, of Red Guards in different cities coordinate and operate in the way Fu Ping described.
The train ride from Shanghai to Nanjing took 4 hours (Page 24). After throwing Fu Ping into a train, the only way "Bent Star" could notify the Nanjing group her train and car number is by telegraph or telephone. This was China in 1966. Telegraph and long-distance telephone were extremely expensive and notoriously unreliable.
After showing minimum concern in Fu Ping's safety and welfare in getting her into the train, it's hard to imagine they would then take such trouble to make sure another group knows how to pick her up in a different city, within a mere 4 hours.