MY OPINION --This is a very cute project. Is your sister an adult or a child? If she is a child I would look for something more basic -- definite shapes and distinct colors.
An adult? Has she had any other experience with other types of stitching. Riolis patterns and kits tend to use different types of threads (wool, cotton, floss, etc.) You might want to start her with something that only uses floss for her first project. After that, she will be able to decide what she wants to do.
This pig is very cute. Hope Sis enjoys stitching it.