In-universe, how old is Miku?

What year was Miku released?

She places third behind GUMI and Shiki Rowen.

In 2010, aluminum plates bearing Miku's image were sent on a spacecraft bound for Venus.

https://noise.thehardtimes.net/2019/08/29/miku-created-minecraft-how-queer-vocaloid-fandom-brought-a-parody-account-to-infamy/

She's in Fortnite. She's in Magic: The Gathering. At this rate, she'll be in your walls.