How many days is a woman in her safe period
there is a window of like 2 days where she is "safe" but in order to figure out that window... she needs to be very acute when paying attention to her cycle.
She would have to use a system called fertility charting... most couples use it to tell when they are the MOST fertile, but you can also use it to tell when you are the LEAST fertile.
It's still not a very reliable way... she would need to be charting for at least six months to get an accurate average and even then your body is subject to hormone shifts and changes(especially at a younger age.)
Its best if she sees a gyno for reliable birth control options, but don't forget only CONDOMS can prevent disease.
I assume you mean the point of your cyce were you suposedly cant get pregnant? if thats the case THERE IS NONE, you can get pregnant at any time of your cycle at rare times you can be less likley to get pregnant, but theres ALWAYS a chance especially since semen can live inside you for up to 7 days so if you arnt going to use condoms at least talk about going on some form of birth control and know the facts before you start having sex
I don't understand your question. Mind explaining a bit?