Melanie Verwoerd (standing in for John Maytham) spoke to young Vuvu Maxwalisa and her nine-year-old brother Andile.
Vuvu has aplastic anaemia, a condition where the bone marrow does not develop in the body and a deficiency of all three blood cell types develops.
Her little brother was a tissue type match for Vuvu and has been able to help his sister live a normal life.
This story highlights why it is important that as many people as possible go onto the bone marrow register.
Contrary to popular believe, it is not painful or invasive and thousands of children die every year that could have been saved by bone marrow donation.
Also: if you want to help CHOC who provides homes for mothers and their children while they get chemo and other medical treatment in Cape Town you can e-mail them on wcape@CHOC.org.za I know they are always in need of second-hand clothes, toys, toiletries and also volunteers.
Listen to their inspiring story below: