Welcome Ben and Susie. Your girl is precious. Without paperwork (pedigree, etc.) I don't think it can be stated definitively what breed Susie is. However, it is possible that she could be a RagaMuffin. That breed allows for any and all color combinations. I wonder if DNA testing could give you the answer?
Here is a photo of my late Pooka...a pedigreed Muffin. She was one years old in this picture.
Forgot to mention that in RagaMuffins they are not called calicos, but rather, tortie point with white.