M Kate's Bag - Balenciaga? Please help ID

The Olsen twins always look dirty. While you can't believe everything you read, one of their former bodyguards told some gossip rag that they go for days without bathing or washing their clothes, because they party and drink a lot. Judging by their looks, I wouldn't be surprised.
 
I just love the simplicity of the bag. Perhaps I simply don't have the eye, but I don't get their style.

Speaking of professionally cleaning bags, how do you know who to go to/trust?

Thanks, ladies!
 
I think I remember seeing pix of her with this dirty white B-bag a while ago, maybe last year (on this site).

I just figure even though she has more money that all of us put together and could buy tons of new B-bags, this is just part of her urchin look.

And is that a skirt she is wearing?
 
More questions...

Forgive me if they're stupid, but does this style evolve beyond the color from year to year? I ask because when I was doing a search, the detailing on what I was finding looked quite different.

Again, thank you!