This is a sad story! The main thing about vegans, I think, is that they eat NO products from animals-- Won't eat eggs, milk, or anything that might have an animal product in it. I think it's a diet heavy in grain, legume, soy, seeds, nuts, fruits and vegetables. You have to carefully combine foods to get the complete amino acid for protein. I'm not sure how you could have this diet for a baby's first few months and I don't understand why they'd be against nursing unless the Mother couldn't for some reason.
I did a quick Google Search and came up with this site for more info:
I know a woman who got paranoid about doctors and actually lost weight during her pregnancy, and got involved with some "nutritionist" due to what I think she thought were food allergies. During the baby's first few months, the baby looked underweight and had an orange cast to her skin. I saw the Mom feeding her carrot juice and I remarked that too much Vitamin A can be toxic. The Mom got defensive and mumbled something about food allergies, and I could tell she saw me as a buttinsky. The child seems fine now, still small and underweight for her age, and I wonder if she's had or will have developmental or intellectual problems...:stone