.. Figure out the DNA evidence

It is the fireplace at Fig Hall. There is a photo of it on the café wall.

Examine the family tree on the photo. Also examine the vases.

You have one in your house!

Talk to Esmé about the vases and the family tree. Then Lucy will pick the vase up. show spoiler Blue crystal vase

Now you just need to get the canvas out of the vase.

Go show the family tree to the police officer at the town centre.