This is pretty common and understandable but there are things you can do to change the situation! :)
Two pretty easy quick things to do...
Show them a week of your cronometer pages and compare your nutrient intake with the WHO standards.
Rent Forks Over Knives from the library and have a family movie night, parents love that! ;)
We get many new members here that say that single movie changed them from a hard core meat eater to vegan overnight.
Please let us know how it goes!
Dr. Neal Barnard's books all say it, widely available at the library.