While I disagree with the guy you answered to, you're actually incorrect, this thread is specifically about Fujino's SAO game rather than canon SAO, so while comparisons and references with Canon are good, just talking about Canon SAO may make the mods delete your comments later so be aware of that :O
Because she was added just as a minor side-character XD Hell, if, now that you actually KNOW all the characters, look deeply, you will realize that NOBODY in this game is even remotely done justice, screentime doesn't equal accuracy because even Kirito and Asuna are both bad parodies of themselves to make the NTR plot even remotely work. Same with Suguha, who had to be completely changed from the very beginning to even make her plot give a NTR-like feeling at all