Does it change? If it gets mature can you say how much?
Is that noticable? and how would it change till then?
Thanks! 
Your voice will continue to change your entire life. A woman’s voice can be affected by training, overuse, health, hormones…it never ends. If you are asking when a woman’s voice peaks, I know professional singers who’s voices peaked in their twenties, many others who peaked in their thirties and a wonderful mezzo who is peaking now in her late fourties. There’s just no way to tell what the outcome will be! Of course, after a certain point age and thinning of vocal folds take their toll on everyone.