no, not herding dogs; sheep guarding dogs. the big fluffy sheep-looking ones, like english sheepdogs, but a lot of countries have their own variety, maremmas, kuvasz, great pyrenees, etc.

whereas herding dogs are bred to look like predators and motivate the sheep, guard dogs are bred to look sheepish and nonthreatening. similarly, whereas herding dogs are bred to exhibit sort of predatory behavior to the sheep, to motivate them, guard dogs are bred just to hang out with them all day. one reason why they make good pets, whereas border collies, for instance, really need to work and can be a handful for folks who just want to have a dog around.

so, if the lab had some of those genes in her background, hanging around a sheep would be natural for her.