Ide like to know why you feel you need to take so much daily to begin with. Codeine is my opiate of choice also, but i always keep it too once or twice a week, which helps with not only money but tolerance issues also.
The withdrawels are well worth it for a few days, and to avoid going down the path of looking for stronger opiates once the codeine stops filling the void.
This is a judgement-free zone my friend. I know you're not being malicious, but we don't like it when people make commentary on people's habits because some people are really shy about their condition to begin with. We don't want to chase them off. Oh, and by the way, the reason she takes it so frequently is because it's Morphine, an Opioid and Opioids are highly addictive.
We have countless threads regarding useful medications for mitigating withdrawal symptoms so I won't dive too deeply into it. Lorne, how dare you chastise my Cannabis intake

Those are fighting words. So, some medications that help, basically in order of how effective they are.
Gabapentinoids - Gabapentin (Neurontin) Pregabalin (Lyrica) Phenibut (OTC Supplement) Gold Standards. Effective for basically all symptoms if you get the dose right. I could be on day 2 of full-blown withdrawal and if I have Pregabalin, I can teach 7 hour long classes with no problem. These drugs should be in any user's toolbox.
Cannabis - It will stimulate your appetite and help settle your stomach. My strategy has always been, smoke and then use that time to hydrate and possibly eat a small meal. It can be very useful to have your food with a glass of water so you can wash down each bite. Also great for sleep.
Clonidine (Catapres) - Helps with hot/cold stuff. Can help you get to sleep pretty effectively. I've always just considered it a minor sedative. It's definitely useful, but the above are really what you need.