Mjnari the name comes from Life Death II. When powerless Ororo was wondering around in Kenya, she got shot by the Fenris twins. She barely lived herself, but then she found a pregnant girl on the road, her bus having crashed in a sandstorm. Ororo helped her back to home village. Where they lived the soil was so poor only a certain number of people could be supported, so when Ororo helped deliver the girl's baby, and gave him CPR to breathe life into his stillborn body, the village elder Mjnari committed ritual suicide to make room. It's a gorgeous story if you haven't read it(Uncanny 198).
The TAS episode is based on that, but they make that baby grown up into a tween/teenager. In the comics timeline, that baby would still only be a child, not even pubescent. I wouldn't necessarily bring the TAS version to 616, even though that episode was pretty decent.
As for Spyke, yeah, he was whack. Storm having a random sister was whack. Storm being older than everyone else and having to be den mother was whack. Evolution overall was pretty whack. If they really wanted a black character in the main cast, they should have a) had Ororo as a teenager too, and b) used a non-time traveling Bishop and/or Synch or Sunspot or Bedlam in the Spyke position.