What happened the first time she brought someone flowers? If it resulted in a positive reaction the child will be inclined to repeat that action, and associate flowers as being a good thing, thus liking flowers. If a child sticks a fork in the electrical socket and gets shocked, you can bet they wont do it again anytime soon because they will associate the action with the pain, and then would avoid the action that causes the pain.

I just used a general example using an action noted previously, which happened to be that of your niece. Remove the words "Freya's" and replaced it with Jane Smith's and the example still holds.