I don't know where she lives but here in cold country mitttens and hats made from old sweaters are very popular.
Here in UK memory bears are the thing at the moment.
What a lovely thing to do. With the left over pieces you could make a drawstring bag, a teddy, scented pouches to place in drawers, heat pack, or Hand warmers. What is the cardigan made from? You may be able to make a few more things depending what it is made from.
You can make leg warmers from the long sleeves???
thought of that ,but my collegues about 45 so maybe not,but thank you for your idea