You can talk all day to an 18 or 24-month old about the brother or sister on the way, and they’ll never grasp the gravity of the situation.
Just like new parents, nothing anyone says can perfectly prepare you for having a baby.
A few ideas to help older siblings navigate the transition include:
After delivery, give the older sib a present and say it’s from the baby.
Catch them being good.
It takes practice and conscious effort, but commenting when you see the older sib behaving the way you want them to is very helpful.
Praise them effusively in situations where they’re:
being gentle
showing affection
saying something loving to or about the baby
being helpful to Mom or Dad.
Involve the older sib in the care of their little brother or sister.
For example, asking them to “help Daddy get a clean diaper for the baby” allows you to manage the newborn care, give the older sibling attention for something positive, and create the dichotomy between a “big girl” sibling and “the baby.”
After all, she is her brother’s keeper.
Once a week, carve out some protected one-on-one time for Mom or Dad and the older sib.
This means the other parent or another caregiver is with the baby so the older sib has your undivided attention.