Ripe fruit is the best carb source since it doesn't cause gut irritation/inflammation. Make sure its organic since higher consumption of conventional fruit equates to higher consumption of pesticides/organophosphate.
From my personal experience and my knowledge of biochemistry is that the best protein source is raw leafy greens since they contain high levels of Vitamin A that gets converted to retinoic acid in the body and retinoic acid naturally stimulates protein synthesis however large portions of raw leafy greens aren't ideal for a busy civilized human, since it is a hassle eating a large amount. Obviously including a good portion of raw leafy greens in the diet daily to fulfull Vitamin A requirements is beneficial for the gut and overall health of the body.
We know that plants are 90-95% water. Lets say we decide to consume 1 kilo of romaine lettuce; thats 900-950mL of water and the rest is nutrients. Less water she has to consume.
Other protein/fat sources are walnuts, pecans, other nuts and avocados. Vegetable fats from whole foods are harmless since they haven't been subjected to heating and oxygen. She can eat as many avocado's as she wants and I highly recommend them.
Then there is fermented protein sources like tempeh, natto, etc..
There is also raw protein powders like Sunwarrior and others I can't recall.
If you didn't know; processed tofu/vegan are the same as eating any type of processed food.
I don't recommend beans since they absorb bile. Bile contains cholesterol and androgen hormones that the body absorbs naturally with fats from the diet but when the fiber from the beans absorb the bile, the body needs to produce cholesterol and androgen hormones again from fats. Hence beans are excellent for weight loss but terrible for the body in the long run.http://www.jlr.org/content/38/6/1120.abstracthttp://naldc.nal.usda.gov/download/39984/PDF
My personal opinion about anyone who doesn't want to eat animal products is to eat fatty fruits for fats needed to produce hormones/neurons, get enough sunshine for Vitamin D and eat raw leafy greens for Vitamin A/K. Vitamin D is required to produce thyroid hormones which regulate the production of lipids, cholesterol and many other functions. Cholesterol is required to produce androgen hormones by the stimulation of retinoic acid(Vitamin A). On the contrary, those who consume animal products don't need Vitamin D levels to be high to produce androgen hormones since they consume dietary cholesterol.
I got carried away however this information should help anyone who would like to be healthy on a plant-based diet.
Is she taking a B12 supplement?