Answer:
17
Step-by-step explanation:
If she has 12 fewer rainbows than stars, she would have 15 rainbows.
(27 - 15 = 12)
If she has 17 more flowers than rainbows, she would have 32 flowers.
(17 + 15 = 32)
And if she has 15 fewer butterflies than flowers, she would have 17 butterflies.
(32 - 15 = 17)