Reading through the forum for the game, I saw someone else having the same problem - this response allowed the player to complete the puzzle:
Is anyone else having trouble with the doll puzzle? As I said before, I have played the game twice, used the strategy guide to make sure I had the geometric shapes on the right doll (I did), but the chest won't open. I went all over the game thinking I must have to do something else first, but no luck...
Did you check the position of the eyes on the doll's faces?
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witter
Waves.