I Agree with this idea. I made my grandson a quilt when he was 7 years old. He watched me make it. A lot of not wonderful things have gone on in his life and through it all he has had the quilt. He's turning 18 soon, and the quilt is showing signs of wear, but he still uses it. I do have a new one planned for him.
So make one with a more grown up theme, but with her interests in mind. If she lives close to you, take her out looking for panels or look on the internet with her. It's the memories of you and her that will really make her treasure the quilt.