Classes in public schools each have an approved "official" set of objectives that are mandatory guidelines for what is taught. Google to find a set of objectives for her age and grade level, and follow that. This will direct you to start "at the beginning" and work up to more difficult tasks in an organized way. Objectives help the teacher and the student, both. A person/student who hasn't first learned the parts of a sewing machine, how to operate the machine, and the skill of sewing on lines (so she can sew straight seams) will not be capable of making garments of any kind.
Sets of objectives are written by people who are skilled in teaching and have knowledge about what students in each age group and grade level have the ability and background to learn. Your teaching will be more effective and your student's success will be more easily accomplished if you follow these written guidelines.