I'm so sorry to hear about your sister. Keep positive during this journey with her because treatments have come a long way. Help her to laugh as much as possible. I'm posting some easy and cheerful quilts that I've made.
1. This quilt is made by making half square triangles using a cheery fabric with white. Then arrange them as diamonds.
2. This is a scrappy using rectangles.
3. This is a Bento Box using batiks.
4. This is a trip around the World that you could make in her favorite color or colors.
Good luck to you and your sister. Please post whatever you make for her.