If she's introverted think of something intimate and warm. Maybe her fav place, you shouldn't make it a stressful situation for her. Maybe decorate her room with many many balloons. Spray perfume, have lights. Maybe buy led lights to decorate it. On the floor scatter decorative material (adera yetekorarete wereket endayhon, lela kelem yalew yemiyamer neger) For many girls her room is a place where she faced many ups and downs, her demons, (if the walls could talk...) it could be such a comforting feeling to take such a big step in her safe space. Good luck, I wish you the best!