What do you think?????

She will love it! Cooking dinner yourself (or together) also adds more of a romantic feel to the evening; it makes it seem homemade. Girls love sweet gestures. Giving it to her after dinner and before dessert would probably be ideal, and you should include a sweet note as to why you chose a butterfly. She will feel like you really listen and pay attention, and she will think it's adorable that you remembered.