Do not ignore your toddler's new behaviors
— address them like you would have before his sister was born. To help him adjust to his new sibling, focus on his role as the big brother. Point out what is “cool” about being the big brother and engage him in tasks that involve caring for his little sister.
Perhaps he can hand you a diaper when needed or help tuck his sister in bed. Give him jobs that only a big brother can do. Make him feel needed and important to the family.
While it may be difficult, share some one-on-one time with your son. Can Grandma and Grandpa babysit your daughter for an hour so you and your son can do something together? This will help reinforce that you still love him. He needs your attention, as hard as that may be right now.
