Jill Walker is a 2nd Lieutenant of Onix Team. She is the second in command for Gold unit, whereas Stan Walker, her husband, is the first in command. Just like Stan, she has been awarded the Medal of Honor. She was also awarded the Purple Heart medal, after she was hospitalized due to being shot in a firefight. She has also refused all promotions to exceed of higher ranks, which kept her as the second in command of Gold unit. She is strict, but soft-hearted wife and mother, and keeps a close relationship with her son, Kyle Walker.
Jill wears an old ACU or Army Combat Uniform with a Combat Shirt instead of a standard Combat Polo, covered by a Tan/Khaki Operator Vest. She wears knee pads and elbow pads, and either a Dark Grey Scout Cap and a communications headset or a Dark Grey MICH 2002 with a communications set. For eyewear, she wears Tactical Shades or Aviators, and sometimes a Dark Grey Balaclava. When on casual wear, she usually wears Tee's or Blouses, matched together with a pair of jeans, and either running shoes or flats.