GSL female wavy bitch stripe

[Snarly]

Nova has a massive wavy bitch stripe!
It has calmed, but a few months ago her tail, back and the fur behind her legs was wavy and almost curly! how is this even possible? Her tail looked like it had zebra stripes!
Does anyone know if this is something that is common in these lines?

Her Dam: http://www.pedigreedatabase.com/german_shepherd_dog/dog.html?id=718216

Her Sire: http://www.pedigreedatabase.com/german_shepherd_dog/dog.html?id=438956 ( absolutely horrid picture of her sire when he was younger..he doesn't look that feminin in person!)

Her parents as well as the siblings I have seen all have a bitch stripe (even the males) but shes the only one so far that is wavy.
Pic 1 is Nova's back on one of it's less wavy days and picture 2 is of her brothers back (his stripe is like brown..not gray/silver like hers)

[suzzyq01]

it's the adult coat growing through the puppy coat. My plush coat boy had this too, he is almost 19 months and it's just about disappeared completely. Give it time.

[Snarly]

She will be 3 in january...
The brother will be 1 in january as well so maybe for him.

[Lucy Dog]

Looks exactly like Lucy's bitch stripe... it pretty common.

[Liesje]

Very common. IMO it is more rare to see black/tan or black/red dogs that have a full solid black saddle than dogs with salt and pepper or bitch stripe. Nikon did until this summer, now he's got a tiny bit of salt and pepper behind his wither.

[Snarly]

I know that the bitch stripe is very common, but what about the wavy fur? I've never seen/heard that before. Her tail a few months ago was so curly that the white underneath curled over the black on top and looked like a zebra.