She had never been mentioned, period, prior to this. No name, no face, no backstory, nothing. This is all new information.
How many of you here suddenly think that Goku and Crono are at least half-brothers?
No more so than when I first saw the animated movie cut-scenes for Trigger. It's Toei's character recycling process at work again. It seems like they've only ever created about a dozen unique characters, and when they need more, they shuffle the names, body parts, and other attributes of those dozen around to make new ones, a la Mr. Potato Head.