Since you are 12 and you say your mom has been a JW for the same amount of time, she probably started studying when she was pregnant. When there is a major change in a person's life such as a baby, people often start to question the meaning of life and if there is a God. That is a great time for JWs to convert that person since JWs will have answers to all of the person's questions. With a baby coming, your mom will more easily want to do what they tell her God requires to 'save' her baby.
Watchtower claims the world as a dangerous and scarry place under rule of Satan the Devil. As such, all the world is against JWs and so will persecute and kill them. For many JWs, the thought the organization being wrong will not even be considered.
Congratulations to your mom for taking the initial step, progressing to actual investigate using information other than provided by WT.
Is your mom also posting on this discussion board?