Ok so as we know adolescent boys voices change, but so do adolescent girls! It is not as big of a change as boys but it is similar. During puberty, a boys voice will change from one octave to two and a half octaves. With girls, it changes but just not to that magnitude.  When girls go through puberty it’s just like the boys, they grow taller, their skull grows, their vocal tract grows, their larynx grows and then you get more resonated space.  So, to all my beautiful adolescent girl singers, know that your voice changes. It can sometimes take a year to three years, but be patient. I know it can be frustrating at times. All you moms and dads, if you have a 13, 14, even 15 year old girl, and her voice is not performing properly, just know things are changing and growing!! There are fun exercises to do, but as long your vocal tract feels free, and you can be patient, things will all be ok!