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