You need to have unlocked magic with the blood thinning potion, then go to Alis' room on Saturday or Sunday afternoon so you can magically peep.
You probably haven't made this potion yet. You need to buy one small magic crystal at the alchemist shop and collect enough materials from the first two collection zones. Check the hints in your room.
Also bro I hope you asked Dianna to store herbs and then asked Kati and Savi to gather them. Free income.