Thanks a lot for taking the trouble to update, a lot of people don't, just post their problems on forums and there are replies and you never hear from them again.The feedback is useful.
It must have been a difficult time for her to be so critical of non-vegans only to end up with health issues. It sounds like she dived in too deep, too fast in a way. Maybe that is why there was a period of no contact? The struggle to reconcile having criticised everyone else, then having health issues.
I personally waited some months before telling my close family I had gone (mostly) vegan and was in to my second year before I mentioned it to a wider group of contacts on facebook. Precisely because I thought it would be embarassing to be saying "meat is immoral" one week and then geting sick the next and wanted to avoid any chance of that happening. Of course, I was in my early days where I was still affected by the bias against veganism and didn't realize that healthy vegan diets are possible for almost everyone, and I didn't understand that getting fundamental, unsolvable health issues on a vegan diet is unlikely - provided you do the nutrition research and don't have specific allergies/conditons/illnessses. So, I think it's unlikely that she needs fish or eggs for health reasons. Of course, there is a small chance I'm wrong and it's easy for me to say that since I've never had health issues due to diet. But she probably just hasn't worked out how to do a vegan diet properly yet. Just depends how serious you are - are you willing to take the time to do nutrion reading, see a nutrionist etc. Health problems are common in the early stages of a vegan diet, but that's more of a transitional thing.
However, it's a reasonable compromise if she was having health issues. Over time, she might go back to veganism or at least vegetarianism. For example, if she learns the best vegan protein sources for her or learns that the Omega 3 in fish can be got from certain nuts and seeds. Even if she doesn't, she will at least have reduced her support for the factory farming operations in which animals have a poor life and suffer throughout their life, not just in the moment of death. I don't agree with hunting, but it isn't any worse than supermarket meat, in fact it's probably better.
Yes, vegans can be annoying. However, that is not in my opinion an argument against veganism, or in favour of eating meat. Imagine that black lives matter activists were annoying and preachy and purist, that wouldn't make racism or police violence against blacks OK. I'm not trying to compare racism with meat eating by the way, it is just an analogy. The point is we should judge veganism by the merits of the argument not by the attitude of its proponents.
Annoying vegans is a reason not to hang out with vegans, and perhaps a reason not to be very purist (e.g. avoiding toothpaste made with an animal ingredient or avoiding a chocolate chip cookie because the chocolate has milk). I think that's the type of lifestyle that would not be helpful for her, and, at least for now, she might want to avoid the type of vegans who insist on that level of purity.
She may have stopped in her advocacy because she no longer feels enough confidence to do so, given the health issues. The word "phase" was that your word or hers? I would suggest not to use that word when describing the situation with family or with her. Because, it may suggest you view her initial judgements as immature, and indicate you still don't take them fully seriously. (Ignore this comment if she herself was the first one to use the word "phase".) Time will tell if it really was a phase or not.
If she has fully understood and accepted the moral arguments for veganism, then it is not necessarily a phase. It is not like dying your hair or liking goth music or going on a low carb diet. It is more of a moral transformation. So, it is possible that she is not going through a phase but has just not yet reconciled the moral and health arguments, causing her to need to back off on the activism.
On the other hand, maybe you are right, maybe it was a phase. TIme will tell as I said. If she's jumped back to the fish and eggs upon having health issues, rather than see a nutrionist or ask for help on a vegan forum, then this may indicate she wasn't totally as sold on the ethical arguments as it first seemed. But difficult to say since I don't know her situation.
Best of luck to both of you.
