Where can I find the statuette?

Hint 1 of 4:

Take a look behind the mirror in the study.

Hint 2 of 4:

You'll find a lock.  Once you unlock that, you should have a good idea of
where the statuette is.

Hint 3 of 4:

The key to the lock is in the library.

Hint 4 of 4:

Look at the book on top of the bookshelf, and you'll find a key inside.