My daughter is a fine arts major and took art classes all through high school. Her freshman year, the teacher had them go buy a large bound book of blank pages. They were required to draw, paint, sketch, or collage something in it every day. My daughter finished her first book and filled another before the end of her senior year. It is such a fascinating journey to watch her art shift and change with her maturity and through the different phases of emotions she experienced throughout the four years. Some of them were whimsical, others dark and angry and a more than a bit uncomfortable to view. But that journal helped with a lot more than artistic skill and expression. It was an excellent outlet. She still keeps an art journal.
Perhaps this is a gift you could give her and encourage her to art-journal once a day. Helping her embrace the transitions and changes may help her accept that her artwork five years from now will be vastly different from now just as it is different today than it was when she was little.