User blog comment:Oknight/Artemis, Cheshire = sisters pretty much confirmed/@comment-173.66.189.214-20110914235012/@comment-64.247.102.126-20110915010052

If Artemis's sister is Cheshire then Cheshire would be older, since Cheshire is taller and has a more mature voice. Cheshire also teased Artemis in "Infiltrator" by calling her kid.