Would it be possible for your daughter to enroll in a school that offers AP classes, rather than the IB curriculum, and thus give her the opportunity of more flexibility… and putting less stress on your spouse to plan for the IB HL/SL courses? In addition, most American colleges tend to be more flexible for AP classes, whereas they only grant credit for HL exams. (A good strategy is to take AP exams that correlate with GCSE/preIB classes if the student is very strong, and definitely if they correlate with the SL classes.)