
As far as I know whites of any coat type are still a fault as far as showing goes.
White GSDs have been recognised as a seperate breed I beleive in Canad, and there is also a European White Shepherd (old fashioned type) and there is a Dutch White Shepherd, and the examples I saw were pure Ice white with dark pigment, and a somewhat Belgian ?Shepherd type coat, finer build, but GSD proportions. Most whites I have seen in UK are in fact cream or Biscuit coloured like golden Retrievers.
You can still enter your girls for fun at Comapnion Dog shows in the Novelty classes. You can enter the pedigree classes also, but her coat and colour will be classed as faults.
Actually there is nothing stopping you shoing her in GSD classes at shows, but you are unlikly to place because of these faults. She is still a GSD, but non standard.
If a puppy in my breed had a lot of white on the chest, or anywhere on the body then it would be unlikely to win at shows, as they wpould be mismarked.