Telling the child different amounts of information in different ways all through their lives is the best option. Just as you will not send a 3 year old child to college, you will not tell a 3 year old child something only a college student can understand. So you have to tell a 3 year old what a 3 year old can understand and keep adding to that as s/he grows older.
Document as much of the adoption process as you can- make notes, take snaps, write down details on your calendar/diary/phone as they happen. You cannot possibly remember everything that happened, so the more you document, the more information and tools you have to share with your child.
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