I have tried converting people and it never works. I have seen people being more willing to die slowly and in pain rather than trying such a different diet as ours. I only started this diet once I had tried and failed with virtually all other diets other than the macrobiotic and Breatharian diets.
If she is willing to experiment with raw milk, there is hope. However, I used to have a permanently runny/blocked nose for years due to my dairy-allergy, so maybe she is also dairy-allergic? Then, again, maybe I'm wrong.
You might suggest her doing the Weston-Price diet. It is more conventional than our diet and, I think, recommends only lightly cooking the food. Then there is all the marvellous tribal Noble-Savage quasi-holiness about the Weston-Price diet that appeals to the more impressionable. The WPers also focus on grassfed and nutrient-rich organ-meats. Plus, it should not be too difficult to persuade her to eat all or most of her plant food raw. The mainstreamish Hay Diet, for example, recommends eating plant foods all raw(ie 80% raw plant food, 20% cooked animal food).
Also, mainstream cooked-foodists are often willing to try eating raw animal food provided it is socially-acceptable. So taking her to a Japanese Sashimi restaurant might be an option or for a steak tartare meal at a French/Russian/Hungarian restaurant. My local sushi bars in Vienna all have sashimi plates available as well. Then there is beef carpaccio and beef jerky which most people do not mind eating, despite them being raw.
Of course, giving healthy food/offering advice to one's relatives can, sometimes, destroy relationships. One acquaintance of mine once gave, not on purpose, some nice, cooked soup to her young grandchildren for dinner. This incensed her evil daughter-in-law who afterwards sent a long letter to her mother-in-law threatening to prevent her ever seeing the grandchildren ever again. You see, she was the type who refused to cook(or do anything) and therefore fed her own children on a diet of 100% junk-food, mostly McDonald's. So she resented being (however inadvertently) shown up as being a bad mother.