Tonker,firstly how remiss of me, condolences on the loss of your father.
She has obtained these items legally. You could choose to contest the will, but as you probably know from the probate process, it would most probably be more cost effective to take the above advice and buy them back. (unless they are particularly rare and valuable decorations).
What do you call 1000 dead lawyers at the bottom of the sea?
A good start
PP (LLB (Hons))!