thanks a lot: when applying for case number

thanks a lot: when applying for case number, the form asks if J2 is also apply for waiver. That is why I am worry about. If J2 an J1 waiver are together approved, Can J2 come back? The other thing is if J2 is not waivered, If she want to change status, e.g. to H4, should she apply for waiver again?