Cut off date of approved petition for my sister and family is 17 May 1999. My sister who is Indian citizen, is at present in Botswana. My nice who is 18 yrs. and approved in petition is aready in US on valid student visa. Can she apply for change of staus indepentally when visa number is available or it has to be together with family . Can she apply before her parents apply or it has to be simultaneous?
I have not looked into this issue specifically but my instinct is that AOS within USA may be problematic for her before your sister gets her green card. As a practical matter, she will only need to make a brief - perhaps a week long trip once to get her green card with the family.