How can i help my child discover her heritage if adopted from africa?

Depends on age: Depending on age introduce your child's heritage to her by reading age appropriate books about her country, showing it to her on a map, and perhaps trying to contact a support group thru the internet. The most important thing to convey to an adopted child is that some babies are born to their mothers, others are especially chosen, and the chosen ones are loved just as much as "born" children.