Is it right my mom made my cousin cry?

Sounds like the fatty deserved it. If she eats that much she needs to have a stern talking to about being fat. Fat.

Ok the "be thankful" comment was un necessary and probably said out of frustration. But at the same time your cousin was making, for a lack of better term, a glutton of herself.(Glutton means to greedily be self indulgent) Your mom may have had a certain amount she expected to spend on the food. Your cousin may have exceeded that pushing mom over her personal budget. How would you feel?

The polite thing for your cousin to do would be to order enough food to be comfortably full. She was greedy to order so much because most people don't need all of that to be full.( I am a plus sized adult and I can't eat all that without getting sick)

Your cousin did take advantage of your mom whether or not she realized it. Your mom could have phrased her comment better, or taken you cousin to the side.

When making comments about weight its very hard not to offend the person and your cousin probably cried because she embaressed herself more then your mom embaressed her.

I think your mom probably didn't mean for your cousin to cry any more then your cousin meant to be greedy. I think they were both a little rude to the other though. One took advantage of the situation and the other was insensitive to hurt feelings. They should BOTH apologize.

In my opinion your mom should have let her eat what she wanted. Sooner or later she'll regret it. It's best to keep comments to yourself. Luckily, your cousin isnt thinking to quit eating.