How will Theo treat his little brother or sister

I know there are many, many months to help Theo prepare for the birth of his new sibling, but now seems like as good a time to start as any. We found Peanut today in the toy box. Peanut is a little doll that I mothered before Theo was born. He is soft, small, and has his own peanut-shaped bunting. He will be Theo's practice baby. We spent some time this afternoon talking about how we have to be very gentle with babies and treat them kindly. Theo interpreted my requests and showed me he "understood" by throwing Peanut, biting Peanut, and carefully inspecting Peanut's ribbon hair. Luckily he likes his baby doll, so we'll just have to keep practicing and praying for a good transition to a family of 4.