Helppp

Does anyone know the name of this one villainess story the fl has like black hair and the ml she likes is some guy w blonde hair, there was a specific scene where she gave him some sort of sweet to kill him or something and he still ate it even though he doesn’t like sweet things??? I’ve been trying to find it and she had like a step-sister that liked playing instruments and she ended up dying by some illness, her “father” was like a priest I think? (IM SO SORRY FOR THE POOR DESCRIPTION) ┗( T﹏T )┛(repost cuz I posted it in the wrong place…)