Does she have the needle in right? Does she have it threaded right? Look at the manual to find out the proper way to do these things on that machine. Every machine is different and the threading may be different than she's used to.; The only way to know is to follow the way the manual says to thread the machine.

If the needle is not put in correctly it will also cause problems. The flat part of the needle should go against the post.

Consult the manual don't just assume you know how and keep that manual with the machine so it doesn't get lost. I have been sewing for 40 years and I a couple of years ago I bought a new machine. Just about every time I use it I have to consult the manual for something. That is the only way you learn how the machine works

One other thing that breaks needles is using the wrong sized needle for the fabric you're trying to sew through and/or sewing a thick item too fast.
You don't say where/how the thread is knotting...a little more info would help us help you.