do you think I have a right to be mad if my sister eats all my vegetarian substitutes?!

Say to her, I bought those for myself (or mom bought them for me) because I'm a vegetarian! If you eat them, I have no food! They're expensive and you have other stuff to eat!
Tell her to buy her own or become a vegetarian if she wants them.

Did you purchase these item yourself? If so I would be angry if she was eating them. I would expect her to pay for part of the item, or buy more to share.

If your mom/dad has paid for them than there is little that can be done. I would be annoyed if someone was eating some of the only things in the house I could consume, when they had other options. I would talk with your mom/dad about possibly buying more(as your sister eats what is purchased for you, and you then have nothing else to eat), or asking your parents to talk with your sister about not consuming the vegetarian substitutes since there are alternatives in the house.

Yes. I would be. I'm vegetarian and while my sister likes most if my "meats" she doesn't do that. If you payed for it that would be worse and if there is nothing els. Make her by you some new "meat" and if she doesn't steal her money from wherever she keeps it and buy it yourself. That's what I do

Vegetarian

Well did you pay for them? If you mom bought them, technically they are for the house, you should encourage her to be a vegetarian. But I hate to tell you, you will have plenty to eat without them, and they are actually not very healthy for you. They contain a lot of sodium and are very processed. It is best to eat things like legumes for your protein and eat natural foods.

http://www.tofurky.com/tofurkyproducts/sausages.html
Tofurky Kielbasa: Sodium 660mg 27%

YES! I would be mad if my family or friend eats all of mine, i would ask them to pay up! I did it to ma because she ate all of my Raw Almond it was expensive . Doctor told me to get it but she ate all ot it. She paid me $10...

You go tell her to pay or ask ma/ dad to make her!

My mom already know that veggies are expensive, it ain't something you would sneak to get foods free. She buy some for me when I don't have money sometimes, dad too.

I guess you do have the right if it belongs to you. My family eats my veggie food too but I just think to myself that at least they're enjoying my veggie food than contributing more to animals exploitation. But I understand if that's all you have and don't have a way to buy your food if its limited.

Yes, of course you do.
If she loves them so much, she should buy them her own (or ask your mom to buy more) or become a vegetarian herself.

every one gets a piece which belongs to them,and shouldn't go after others',hopefully she would understand.

YES.
Oh, M.... I have this same problem with my brother! He always eats my cereal >.>
I understand your fury.

Yes, I would be mad too.

Yes, you do. Tell her to ask for them herself.