At my kids’ school most of the IB STEM courses are combos IB/AP. So the same course preps them for the AP test and the IB requirements. It may be the case at your school? I can’t picture your D taking IB Chem SL and AP Chem as two separate courses? I would think too much overlap. If you can get her schedule and share it here, we can have a better idea of what kind of workload it is.