Concubine Nian had three sons and one daughter. Aixinjueluo Fuyi was less than one year old. Aixinjueluo Fupei died just after birth, and Aixinjueluo Fuhui lived to be eight years old. Yongzheng was very fond of this child and buried it with princely etiquette. The issue you mentioned about the naming of the three children is because of the dates when these three children were born. Those with the surname Hong were all before Yongzheng became emperor. The names Fu Yi and Fu Hui were born in the last year of Kangxi's life, when Emperor Kangxi was in poor health. They were probably named to celebrate Emperor Kangxi's good fortune. In fact, Concubine Nian was still influenced by Nian Gengyao.