New family member and acceptance
The jealousy between brothers/sisters can't be avoided. It comes from the day the second child is born. It is a hard work for the parents to explain the first born child how much they love him but that they have to pay attention to the newborn child, too. There are so many tough moments, and we can't judge our children for their reactions to changings. But, also, our approach is very important, as the child sees the world through our eyes. Our goal is to keep their feelings safe and give them double love when a newborn comes into any family.
In theory, things are quite simple. Unfortunately, in practice, we fail to do things perfectly. Children are so sensitive and parents are humans, and there are so many issues coming out from the first day of living as a four member family (or more).
Mommy, I loved when I was your only child
As any mother who gave birth to more than one child, I experienced difficult moments when my second daughter came into our lives. As a family, we felt we were complete in a four member family. Our first daughter was extremely excited to have a sister, but, unfortunately, things seemed more complicated than we've ever imagined, especially because our first daughter is not a pacifist, but more a warrior and very temperamental. A child accepts his sister/brother until the moment of sharing (sharing toys, things and even his own parents).
So, this is the beginning of an everyday battle and later, reconciliation. Things go wild when both of the children grow older and their spirits are more powerful. As a mom, it is very difficult to balance things, because each child has his own point of view, and, sometimes, they feel unjustified and jealous. "Mommy, I loved when I was your only child!" came like a knife in my heart when my older daughter told it to me. I understood that she needed her own moments with me, that she missed me, literally. Every mother makes mistakes, and one of them is that it pays more attention to the youngest child, which the eldest doesn't understand. It is a titanic work to struggle every day with the same problem, explaining the eldest child why it is so important to take care of the youngest one, as you did in the past with him. I'm sure mothers with temperamental children understand what I feel and they have to work hard to equilibrate things in their families, with the hope and endurance that one day, their efforts will lead to results.