Mado G,
I have been struggling with cross dressing since I was 8 or 9. Many others on this site can tell you their experiences. I have purged and rededicated myself to "leading a better life".
After 50 years (yup, 50), I started going to a therapist to take care of this once and for all. I said that I wanted to be cured of this and in a way no one had to know.
I did much research on many sites, articles and books. I started with learning about cross dressers and found they all said the same thing. I kept working with my therapist and after 2 months realized it never goes away. It will always come back.....I was a little confused because comparing myself to them, didn't really match up. So I continued my search and instead of "being cured", I came out MTF to my wife of 25 years, about 4 months ago. My three teens do not know yet but probably will in another year or so.
That is my personal story. However, as I stated, do research. You will see it time and again. All of the sub genres of Transgender. It does not go away. It may fade if you are really busy and pretty happy and distracted. However, it will come back. I don't know if reading this to her would help? There are also SO parts of the site. Perhaps she could get information from other SO's?
I wish you luck and love and a smooth journey.
With warmth,
Joanna