You tell your niece to do exactly what I used to do - and my 1/4 inch seam was awful.
Then I figured out that the needle doesn't go anywhere but up and down, so I needed to watch how I was feeding the fabric through the presser foot. I also purchased a 1/4" foot. Those two adjustments improved my 1/4" soon greatly.
Just shows that the technique that works the best for you is the best technique to use!