He's my nephew, and you're my family. I'll be here as much as you want.
Jessica in "The Slave of Duty"

Jessica Brooks is a recurring character who first appears in the Season One episode "Machismo." She is the sister of Haley Brooks, the late ex-wife of SSA Aaron Hotchner.

On Criminal Minds

Nothing is known about Jessica, other than she is the sister of Haley Brooks, Hotch's ex-wife. She first appears in "Machismo," helping Haley arrange a birthday surprise for Hotch. She then appears in "Seven Seconds," Haley has temporarily moved in with her while she and Hotch had separated. She later appears in "The Slave of Duty," helping Hotch take care of Jack after her sister was killed by serial killer George Foyet. Knowing that Hotch will never quit from the BAU, she offers to babysit Jack whenever he has to work. Hotch presumably accepts as he is seen on duty again in "Retaliation." Jessica reappears in "Route 66," taking Jack to visit Hotch in the hospital after he had severe complications from a stabbing attack by Foyet. She reappears in "Boxed In" when she watches over Jack for Halloween while Hotch goes off to investigate a case. She reappears again in "A Place at the Table," where she agrees to take care of her father Roy when his Alzheimer's worsens.