So there was this movie I remember watching in the 80's. I was pretty young - like 5 or 6 - so it's pretty fuzzy. It could have been made earlier than the 80s, though. Anyway, the premise was an old lady (I think - it could have been an old man I suppose) took in orphans to live in her home. She was kind of cold, but took decent care of them. A new teenage girl came to live with them, but didn't want to be there and was mean to the other children. I remember a scene where they were doing garden work and she stepped on a rake or hoe and gave herself a black eye. She might have run away, too. She starts to get flashes of memories (I think) from her childhood, and finds something (a diary maybe) behind a loose brick (possibly in the fireplace, but possibly in a wall). It ends up that she was the old lady's granddaughter, but that's all I really remember.
Like I said, the details are fuzzy, so some of the above might not be totally accurate. I was definitely billed as a children's movie, and I want to say it was a live-action Disney production, but I can't be sure. Anyone have any ideas?