Oh no, I'm so sorry to hear this.
You might try Google for ideas. Search ideas for when a child is born still, as well.
I used to belong to a forum with a large number of women whose children did not survive (late miscarriage, born still or died in infancy), and every one of them appreciated remembrance of their babies. These children are just as much members of their families as any living children, and it is a testament to your good heart that you are thinking of remembering her in this way.
Peace to you and your family.