adopting older kids w/ biological children in the house - questions

I wouldn't take down anything that was already up. I would celebrate the entry of the new children into the family by having new pictures of them made and added to the wall and also do a family pic. Pictures show the history of a family and the changes that occur over time. You can do everything you can to get pics of the kids before they came home and if you do, put those up. I would also start a "baby" book if you have those for your other children.