When will you tell your older kids?

Danelle • Appalachian American🏔 Mom of 2 princesses 👑
If you have kids already, when will you tell them you are expecting? I have heard a lot of people wait to tell them in case something happens, they don't want them to be sad... Also a lot of people don't tell early because they don't want their kids to have to wait sooooo long to meet their sibling! What is everyone's plan?