I think this is BlackRose, not Rena.

That image is taken from the manga Tasogare no Udewa Densetsu, so is Rena.

Is it indeed from a manga?
Rena is like a younger version of BlackRose.
This got me thinking... post #70607

BlackRose and Rena share avatars, Rena's is a direct copy that was given away as a prize. For some reason though .hack//tasogare....'s characters are all chibified, and Rena's player is younger than BlackRose's was.

Only Rena, Shugo and Mireille are "child forms" from the previous avatars. I don't know why tough (Balmung, Wiseman, etc. still look adult...)

This has two better duplicates, adding this artifacted one to JPEG death row.