[Jeanette X]

My voice changed almost overnight in Jr. high. I was a little girl with Greta Garbo's voice-without the accent.
I read this on a public speaking website:

"Women's voices are generally lighter & higher in pitch than men's. It is difficult for us to compete there, & research shows more credibility is given to people with deeper voices. What can you do? Practise deepening your voice. It is possible to change those high notes & use them less often. If you are blessed with a deep voice, practise varying it also."

You might also want to try a speech therapist. Other than that, I have no other ideas.