You might want to add some wool felt pieces in bright colors and embroidery floss in pretty colors. You could cut the felt into various sizes of flower shapes or cut into various sizes of geometric shapes. Keep the pieces in size that would be easy for her to hold, not too large or small.
Both my kids liked to sew pieces of felt on top of each other at that age. The wool felt is easy to hold. You don’t have to make a specific project (though you could) but simply let her sew the pieces in whatever way she likes.