She could do some neighbourhood fundraising and donate the money to a charity with a high efficiency ratio. One charity that I like is Chalice. It uses over 90% of its funds for direct poverty relief, and our family sponsors a child through them. In addition to child sponsorship, Chalice has a gift guide where you can purchase medical care, bedding, school supplies, food, roofs and floors foe houses, etc. UNICEF is another (more obvious) choice with a similar mandate.
IIRC, your daughter is now reading (hooray!!)--would she like to volunteer at a library or public early learning center to read to other children? I used to do that at your daughter's age and loved being able to support other children. Another idea is to visit children in long-term hospital care with fresh stories, games, and good conversation. A little cheer can go a long way for a young child with a serious illness.
It's wonderful that she has such a strong sense of social justice!
