My mom and sister think I'm going to develope anorexia: does this sound like I am?

Your body will tell you if you need more calories. That seems like very little food to me, but I'm a guy who exercises a lot. If that amount of food makes you full, then it's enough. If you hungry a lot, then eat more. Your not anorexic unless you eat then gag yourself to throw it up, so you'll get the false feeling of fullness.