What factors stop you from becoming an amazing singer do some people just develop faster than others

Good question! In my experience, students who improve the fastest keep a positive attitude about singing; they're willing to make mistakes, crack, sound "weird", etc; they build the habit of singing into their daily lives; they keep track of their progress in some way (usually recording themselves and listening back); and they stick with it for a long period of time (several months of consistent practice & repetition)!

thank you but I  mean several months is not enough time to become amazing singer but if i want to really good. is it possible to become really good with hard dedicated practice for years

I believe so, Natasha! As with anything, there's a range of natural aptitude. All we can control is what and how we practice. 

hi my name is sandrea how do you sing so beautiful and  that people its amazing

Thank you, Sandrea! Years of listening, training and practice!