Here is the full list of all 21 White Lavender achievements.
Reach 10 witchcraft.
Cure your sister.
Defeat all boss enemies.
Explore all areas.
Collect the pencil.
Find all kettles.
Collect all ingredients needed for the special tea.
Find the purple ball.
Collect all 3 holy scribbles.
Reach 10 might.
Wear a hat that's way too big.
Collect 8 mug shards.
Get pranked.
Meet the mayor.
Wear all blue wizard items.
Take Meggie to the end
Reach 10 agility.
Wear sunglasses.
Cure your sister within 60 minutes.
Find the four-leaf clover.
Find the split pistachio helmet.