bullshit. she was 12 in sao, and this game is at mother's rosario arc, meaning she'd be 14. japan's age of consent is 16. why the fuck give her the same name then? it makes 0 sense. where's yuuki? why even use the same arc name when it's got nothing to do with it?
		
		
	 
Actually, she's younger if we go by one sidestory, she pretends to be/looks like a 10 years old XD And reminder, that's just the age she pretends to ACT: Canonically, Yui and any AIs like her that exist in the non-canon AUs did NOT exist before SAO, she was created alongside it, so if we judged her by IRL-time instead of the age she acts when she wants to, she techically would be just a bit above 2 years old by the time SAO/Aincrad ends 

 (Fujino specifically gave her that grown-up body to fully separate her from that). Also, LMAO, Fujino hasn't respected the SAO timeline practically since the beginning, hell, even things that should have happened in the past are retconned to be completely different if he wants it so (Like how the entire Fairy Dance Arc didn't happen, Asuna's dad just magically and conveniently found out what Sugou was doing and saved Asuna himself). Yuuki may not even exist in this timeline, same with how Alice and Administrator are just glorified OCs with the faces and names of the canon characters, and the others are barely a step under that with how nonsensical they act practically nothing like their canon-selves XD
It IS bulshit, but the excuse Fujino is going with is: Kayaba made Yui over 20 years ago, so she's 21 in this timeline...which is dumb, is on the same level of putting "All characters within this work are +18" before a doujin/H-game starts, and it's a doujin/game of characters you KNOW are in high school and much younger, only worse because he tried to 'explain it with in-universe logic' which is just a giant plot-hole...he probably didn't even think it over properly because of how limited his SAO knowledge is, but 21 years ago Kayaba was 7 YEARS OLD, LOL. So even putting aside the fact that there would have been no technology to create something like Yui back then (Extra so when you remember Yui can only exist thanks to being created alongside SAO itself), he would have had to somehow made her while in kindergarten for the 'explanation' to fit timeline-wise 
Like the countless canon/logic-contradictions that fill the game, you're just supposed to nod along and not think about it, otherwise it's very obvious nothing makes sense at all :3