Well they don't need very much organ meat, just a couple of chunks once a week (obv varies depending on weight and individual dog but thats about average for a yorkie). Otherwise it acts as a laxative.
One thing to remember is that there is no absolutes, what suits one dog may not suit another. The best thing to do is read lots and lots of info on it and take wisdom from them all. For example I know raw fed dogs that have not touched a vegetable in their life and are very healthy, I know others who don't do well without it. Its all about knowing your dog. There are lots of great books about it, but as I said don't take any book, or any website as the final word, learn from them all.
Here are a few quite good websites,
http://www.rawdogranch.com/ http://www.njboxers.com/faqs.htm http://www.naturalpetcare.co.uk/nutrition/dogdiet.htm http://www.holisticvet.co.uk/nutrition.htm http://rawfed.com/
As I said these websites each give different information, the key to it is to understand that there are all sorts of different ways to feed a raw diet, find the way that suits your girl best. On the first website there is a page about how to switch a dog to raw slowly, if Zoe has a sensitive stomach and as she has allergies it might be a good idea to do it this way as you can gradually add each new food slowly so that you can pick out and eliminate any that are causing her problems.
It is common for people to think that dogs cannot get all the nutrition they need from raw food, but if you do sufficient research, understand what sources provide what necessary constituents then there is no problem. We do not appear to have this problem feeding humans after all, and think that it is necessary to have an "all in one" prepared diet for us!
With all this commercially prepared food we will all lose the knowledge in how to construct healthy diets from raw materials, something our forefathers managed for years.
I say go for it, raw feeding is not for everyone but if you are brave enough you could really see huge benefits in your dogs health because of it.