Her main concern here is children and in most cases with kids it's not even mental illness. It's just normal behavior.
She told a story about a boy named Andy who had two loving well adjusted parents. They later gave birth to a special needs little girl who needed a great deal of attention. Andy noticed that he was getting less attention and the baby was getting more. The baby was a girl. Andy decided that his parents loved girls more than boys and so he said he wanted to be a girl. The parents recognized the problem and took steps to put the boy at eased. Problem solved. She made the point that today the kid and the parents would immediately be in trans sex therapy, the boy would be on hormones and scheduled for surgery.
And she's right...this stuff is rampant. I read that in California a decade ago schools reported something like 15 kids a year with gender confusion issues. Last year it was 2,200.