My theory is that the pills are something like a restraint to her real powers and is also the reason she was supposed to die, according to the real plot, so technically her father is trynna kill her. Or her father could also be decieved by the temple or hes an accomplice, not sure. (her father looks too kind im sus and he keeps pushing her to consume the pills and im guessing why he doesnt approve of the marriage is because the duke is very influential and he could know about the pills, which will obviously cause direct suspicion to the temple, because that is where it came from) thats my guess tho. Anyways, thank you to the scanlators <33