I am hoping you can help me find a book I remember from my childhood (probably 40 years ago). The book was about a young girl who lived in an apartment (I believe) and was very lonely. Another young girl moved in and they became best friends. One of the girls found out her family was moving and she was very sad and worried about making a new friend. The first girl gave her a smooth stone and told her when she was lonely to hold the smooth stone and she would feel the warmth of their friendship.
At least this is how my memory recalls the story. LOL!
If I recall correctly the cover had a light blue background and the girls were sitting on the steps of the apartment building.
I have tried to Google search this to no avail.
I am assuming that this book may no longer be in print. Thanks for any help you can provide.