steamed veggie mixture w/ tofu
simply and healthy
or a fruit salad. (turn it into a parfait with some yogurt and granola) doesnt even require any cooking
vegetarian chili is always fun too, be creative
References :

take some celery, and some cream cheese or peanut butter (cream cheese is better),
put the cream cheese/peanut butter on the celery with a knife. its great. and dont be a vegetarian, it just turns you into a big walking vagina.
References :

veggie chili
veggie burritos
bean burritos
cream cheese and cucumber sandwiches
omelettes
sloppy joes(buy dried or refrigerated soy)
pasta with lots of veggies and some soy in the sauce
mmm
References :

Try to make something similar to what your family is eating, but substitute tofu, TVP, eggs, or just ask your mom to leave aside some of the food without any meat in it, depending on the situation. If your family is having a meat based meal try bean cakes.

here is a tasty recipe that can be used as burgers or eaten alone (my personal fav.)

http://allrecipes.com/Recipe/Homemade-Black-Bean-Veggie-Burgers/Detail.aspx
References :

just eat what she makes but take out the meat and be happy… but if that doesn’t suffice, you can just ask her not to make it with meat and after it’s done remove however much you’ll eat and then let her cook the rest with meat. also, if you go to trader joe’s there is a lot of the morningstar brand veggie meat that you can make easily by microwaving or frying on a pan so now you have nothing to worry about
References :

try the internet with the phrase "quick and easy vegetarian recipes"

vegetarian times is a published vegetarian magazine with recipes plus additional information at http://www.vegetariantimes.com

happy cow has recipes,information on vegetarian restaurants,vegan restaurants and health food stores worldwide plus additional information at http://www.happycow.net
References :
http://www.vegetariantimes.com

http://www.happycow.net