gracegagnon. I also am not a mother, but am looking forward to starting a family soon.
It's awesome that you have been standing your ground. After all, this is YOUR baby and you know what's best for you child and you are using your best judgment and intuition and what's been working best for you.
I agree with Elizabeth's advise, that is to give your family and friends some literature.
This is a very touchy subject as it's gotten to the point your sister has called DSS. It must be very difficult for you as I have thought for hours about how I will deal with my family when that time comes, so I truly admire you for being such a strong woman.
Here are some ideas that I have had, having not been in the situation I do not truly know the best way, but I do hope that it helps at least give you some of your own ideas...
Printing up literature specifically relating to children on a raw diet. Jinjee and Storm are a wonderful couple. I've corresponded with Jinjee over email when I had some concerns. Here is her website that there's pics of her beautiful RAW babies!
http://www.thegardendiet.com/
Perhaps have a meeting with your family and make sure to have someone that supports you with you. This gives your family a chance to feel that their concerns were heard. This way you know exactly what to address.
If there is a good doc in your town that can maybe do a live blood test or do a check on your baby that can give a report for you to show that your baby really is happy and healthy. (and by good doc, I mean a doctor that actually knows about nutrition and health, not disease and death)
At least if you try something like these suggestions, it shows to your family that you really are trying to do what you think is best for the baby and the information that you have shows that you are doing what's best.
I really hope this helps and you are able to stay healthy and happy with your beautiful baby and keep happy relations with your family too (maybe even get them raw?!). You will be in my prayers