When a new baby comes into the family, I think it is important to make sure that the older brother or sister feels important too. When everyone is asking about the baby, wants to hold the baby and bringing gifts over for the baby, the other children in the family might feel left out.
That is why when I had a friend that had a baby I made an embroidered blanket for the baby and an embroidered shirt for the big sister. Here are pictures of shirts I have done in the past . . . one for a big brother and one for a big sister.