Natural bobs are usually tapered at the end...the verterbrae don't abruptly end like you'll find with a dock job. Often natural bobs are kinked or hooked too.
That's an obvious dock job to me...it's long and you can see the abrupt end of the vertebrae. You can often see a scar at the end too, depending on how good of a job they did when it was docked. A vet will pinch some skin, and put in a stitch so they don't have a scar. Homemaded jobbies will often have scars...since they just clip 'em off, or put on metal rings or rubber bands until the tail dies off.
The black tri color and irish spotting pattern is really, really, really common in many breeds...and smooth coats are dominant...so she could be just about anything! But with that tail, I'm going to believe that at least mom was a docked breed.
"I don't have any idea if my dogs respect me or not, but they're greedy and I have their stuff." -- Patty Ruzzo
"Dogs don't want to control people. They want to control their own lives." --John Bradshaw