Speaking about numbers [1], there are ~100M of non Latin American females and almost 38M of African Americans. According to the fact that we have a number of prominent American female Wikimedians, I would expect that we have a couple of prominent African American Wikimedians.
http://en.wikipedia.org/wiki/Category:African_American_Wikipedians
146 who use template {{User afr-amer}} on user pages. i don't know who is active in wp
female:
http://en.wikipedia.org/wiki/Special:WhatLinksHere/User:Merewyn/Userboxes/Wo...
http://en.wikipedia.org/w/index.php?title=Special:WhatLinksHere/User:Disavia...
http://en.wikipedia.org/w/index.php?title=Special:WhatLinksHere/User:Hmwith/...
http://en.wikipedia.org/wiki/Special:WhatLinksHere/User:Rhanyeia/User_female
http://en.wikipedia.org/w/index.php?title=Special:WhatLinksHere/User:UBX/fem...
but... not everyone want to use these templates
przykuta