"We did everything we could to make him realize that the baby's coming was not going to diminish his father's and mother's love for him."

After the conception, Wu began telling the son to do things he was capable of to help take care of himself, his mother, and eventually his sister.

In doing so, she wanted him to have a sense of being involved, of not being neglected, as well as to make him feel the responsibility of being a big brother. Wu ways she is happy and grateful for the way her son has reacted.

The boy not only helps change the baby's diapers, but also tries his best to make the sister happy and laugh, especially when she starts crying, says Wu.

He knows the infant needs mother more than he does to fall asleep, so he asks to sleep with mother and sister together when the sister has fallen sleep.

Sometimes when he hurts his sister unintentionally, such as when he presses or kisses her too hard when he is trying to show his love, Wu does not scold him, and tells the father and the grandparents not to scold him, because even if he hurts the girl, she realizes he does not mean to.

Apart from the fact that he does not really hurt the infant, scolding him or punishing him will be detrimental to the relationship between the two, says Wu, and for the boy playing with his sister is also a learning exercise.

"Raising a second child is not about how the first child treats the little brother or sister, it is about how you treat your children," she says.

How to raise two children

Yan Yijia, a psychotherapist in Shanghai, regards a second child as a gift to a family that will help the first child develop, but many Chinese families need help to better cope with raising two children, she says.

She has helped families resolve parenting problems related to raising a second baby for two years.

In China, psychological support for families parenting a second child is new, because most young parents were born after the country's one-child family planning policy was adopted in 1979, and they were raised in one-child families, which means they have not experienced having a sibling, Yan says.

The parents of these young parents do not understand the issue, either, because they grew up in times of material scarcity, when care for psychological and emotional needs took second place to making a living.

"Children can be very sensitive, and they can also be very sensible, more so than parents think," Yan says.

Parents should not seek permission from their firstborn to have a second baby, she says.

"It is the right and the responsibility of the parents alone to decide whether they want another child. If they feel the decision needs the consent of their child it means the positions of the family members in relation to one another are not right and the parent-child relationship is unhealthy."