Jeanette is a member of of the Gallia Knight Army with her brothers Jack and Bleu. She worked with Sheffield to kidnap Louise.
Like her brothers she is seen wielding a weapon, a poison dagger which paralyzes it's victim. Also, like Bleu she can jump large distances and great heights. One of the few times we see blood in the show is when Jeanette slashes Louise's hand. She has yet to show signs of being a mage, but since her brother Jack is a confirmed mage it is suspected.
After licking Louise, she said she could taste the power whether or not this is an ability is yet to be confirmed