Oh my goodness...her coloring reminds me sooo much of my Stedman's!! I mean it is almost exact!! He is 5 months and 3 days old, and his coloring (was) identical to hers...up until the groomer screwed him up and cut his hair WAY too short

...now he is solid silver on his head....and a darker silver on his back.
But I swear, right before we had him groomed (which was only 2 weeks ago), he had the exact same coloring as your little girl

He had the silver stripe down his back....he looked like a little skunk

lol.
Stedman started getting ALOT of silver on his head at around 3 and 1/2 months of age...and I started to notice the silver comming in on his back at around the same time. However, he is still totally changing color and of course he will be for a while

It is so interesting to watch them change...and even more interesting when you go back and look at pictures of them when they were younger and they are a totally different color! lol.
By the way, your baby is such a beauty!