If it wasn't her 'nickname', the explanation for its inclusion makes no sense.
Even the nickname would be potentially identifying, so it might be redacted.
As I said previously, I think the length of the redaction makes it unlikely to be a nickname. And as I also said, I'm perplexed because I see no explanation that fits all the apparent facts. I'm hoping the defense reply might give some clues (or better yet, spell it all out).