I will be surprised if its the food as she is now 9 months and always had JBW.
JWB has been taken over by pedigree pet foods and I have heard several ppl say that their dogs have got the poops recently, pedigree only said they would stick to the JWB recipe for a certain length of time, I think they could be fiddling with the recipe and adding the usual pedigree cr*p ingredients etc.