I know of two people who purchased a toy machine for a child and totally turned them off of sewing.
Find a good basic machine for her and she likely will be using it for many years. You might check used machines at your dealer. Also check to see if they have classes for kids in the summer, the tec school here also has classes for kids. Give her a couple of sheets of notebook paper to sew on the lines with no thread and she will be ready to sew.
In my opinion older machines are tougher and withstand more user mistakes than one with plastic gears and electronic features.
Blessings,
Sharon