Answer:
She would only need to add half (1/2) a cup of flour.
Step-by-step explanation:
Think of it as when you are counting quarters. They go by 1/4's. So, let's say you need 75 cents ( 3/4 ), but you only have 25 cents ( 1/4 ). You would need 50 cents (1/2) to be able to have 75 cents!
Hope this helps you out!!! (: