The most important things I learned in four years of group classes. (Actually, mostly I was unlearning bad habits.)

If it hurts at all STOP!

Have very good posture.

Eliminate any tension in the face, neck, shoulders, throat, tongue.

She may be able to enroll in free non-credit classes singing classes at sbcc.edu

The classes are advertised as being for older adults, but anyone over 18 can enroll. I am not sure if you need to live locally. Once someone from Japan came to class. They are currently being taught online using Zoom.