Children's mystery about a castle and a reclusive artist with two different colored eyes.

[Melissa]

The only things I remember about this book is that it took place in a castle, there were a group of children staying there ( I can't say if the children are related to each other or how many there are). A lady artist is also staying in the castle. She is a recluse with two different colored eyes. One eye is amber in color. I cannot remember what color the other eye is. I think the artist had suffered through an accident that caused her to be a recluse.

[Lobstergirl, au gratin]

When did you read it?
What country/time period is it set in?

[Lobstergirl, au gratin]

Melissa, are you still looking for this or did you find it?