It's been driving me crazy, but I'm trying to find this animated movie (probably early 90's late 80's) about a girl, I think she's a princess and there's a scene where she's running up a long stone, spiral stair case in a castle. She finds a secret room with a stain glass window that has a rose on it and when she touches the window it dissolves.
I know it's vague, but that's all I can remember... Thank you!