Re: kind of upset..
Hmm. I'm sure she believes what she's saying, but I don't know that it'll all that true...
In many parts of the world, people NEVER eat/drink dairy products, and they're just fine. I'm sure some internet research can tell you the best foods to supplement your particular diet.
As for the nursing, well, there are lots of tandem nursers out there. I know there are some very informed preggo w/nursling mommas on the Pin - maybe you can post on the pregnancy board there and see if they have suggestions?