In the beginning, which was just two years ago, I used my son’s beginning piano books for fun on my own. These were from Madonna Woods Piano Course for Christians. You would have to change the fingerings. I used the supplementary books. She has ones with gospel, Christmas, meet the composers, patriotic and Sunday school songs.
For Christmas, a wonderful book is by Daniel Burton in his Easy Harp series. These are easy but yet pretty.
(Not sure what my harp teacher would have thought of these books. My actual harp lesson was out of the Sylvia Woods beginning book and I played a hymn from a hymnbook on the piano to help me get back into site reading, etc. It had been over 30 years for me.)
I totally understand her desire to play something. That is why I got the old beginning piano books out.
Maybe this will work.