You could just try to let her get close to you, instead. By just being casual and nice around her, you can show her that's a good person and something worth being around.
If you really would like to help her feel more at peace, there are many symbols of peace. And easy option to help encourage it would be to take a white candle and carve her name/initials and a white dove into the side or bottom, and then burn it for her. Or, you could place a white candle over an image or in front of a representation of one.
Also, the color yellow is said to be representory of happiness, possibly by presenting her with a bouquet of yellow flowers, or something wrapped in yellow paper would help.
These are just a few of many possible ideas. Good luck in your endeavors.