I came across your site because I was searching for images of dogs that look like our little rescue boy, Stewie.  He's about 11 pounds, 7-8 months old, and looks very much like your Miss B.  Even the Vet said she believes he's mostly wire haired Jack Russell, because of the face and tail markings.  So I was curious to see what Miss B had in her lineage.  Imagine my disappointment!  I'm thinking that this doggie DNA stuff is flawed.  I choose to believe that our little guy is definitely part Jack Russell, and maybe a sprinkling of something else, but whatever--he's a little pistol who regularly outsmarts us and has boundless energy.  I think we'll keep him!