I was watching X-Men: the animated series last night (yes, I still watch that show lol) when I discovered a Black Female Superhero I didn't know about. Her name is Hope and she's a member of the team Clan Chosen.
She is from the future and is led by Cable, who turns out to be Cyclops' son. The mission of Clan Chosen is to fight the armies of Apocalypse - and anyone who has read the X-Men comics or watched the show knows how despicable a character Apocalypse was.
In this particular episode of X-Men (Beyond Good & Evil Pt. 1 - The End of Time), Cable goes back in time to prevent Apocalypse from destroying the world (again?).
Hope doesn't have any powers, but she's a proficient weapons expert. Outside of the X-Men cartoon, her character first appears in Marvel Comics' Cable #1.