LOL - the definition of "RMB" is raw
meaty bone. If the book didn't mention what proportion should be meat, it does at least imply that it needs to be substantial (or else it's just a bone, not a meaty bone). It is a bit difficult to say percentages, of course - since that's going to vary according to which boney part it is you're feeding.
A better way to look at things, perhaps, is to say that you're trying to
emulate the feeding of whole carcasses. You might
not feed whole carcasses (and with the possible exception of chickens and rabbits, few of us ever do) but the proportion of meat to bone to offal should approximate that which the dog would have consumed had he been given a whole carcass over several meals.
So. How much meat versus bone would your dog be consuming if you bought a whole chicken and cut it up into meal sized bits? The answer, clearly, is a heck of a lot more than comes on chicken frames and necks

Now that doesn't mean don't feed necks and frames - they're an extremely useful and cheap food item. But it DOES mean that if you feed a lot of those items, you *must* add meat to ensure that the dog is getting adequate nutrition.
Does this make reasonable sense to you? All parts of a carcass are valuable nutrition for a dog, you just need to ensure that what you feed does, over time, include or approximate all of them.
Actually buying whole chickens can be a very good and economical way to go. Commercially raised chickens do have a bit of an excess of meat, so that whole chicken can feed both the dog and people. There are plenty of raw feeders (myself included sometimes) who go out and get a whole chicken, take the breast meat off for themselves, and then cut the rest up into meal-sized portions for the dog. Since you often find that buying chicken breasts costs as much (or more) than the entire chicken, doing it this way effectively means that your dog may be eating "for free"...
So that's one option. Another is to buy the necks and frames - which is also an attractive option since they're cheap (sometimes even free). Then add meat (be it chicken, beef, lamb, pork or whatever is cheap at the time) in an amount that approximates the flesh that would have been on the carcass if not removed.
A further option is buying chicken/turkey portions. They're very often findable at reasonable cost, especially frozen. Things like legs, quarters, thighs are excellent in terms of meat/bone ratio. Wings not so good - as mentioned, they're almost exclusively bone and skin (which is fine as part of a meal, or part of a diet - but pretty useless on their own).
None of it is a rigid requirement however. It isn't going to hurt if one meal is quite boney and the next over-meaty. Some meals might have offal included, others not. Just as with variation between meats, it's balance over time that counts. No need for every meal to follow strict criteria (any more than every meal you eat needs to). In the particular case of your dog though, who seems to be having a little trouble, it might be a good idea to see how she does with more meat first, and only later let a bit of variation slip in there.
Oh - and egg shell. Not all dogs will consume it. It's a nice bit of calcium for them if they will, so I'd suggest crumbling it up quite small and hiding it in ground meat. If she still picks it out, you could try putting it through a blender or food processor - or just forget it. It's not the end of the world if she doesn't want to eat the shell.