The importance of learning from mistakes is so that you will not make the same mistakes (or similar mistakes) in the future, and you will thereby make more right decisions and fewer wrong decisions, and therefore will enjoy more success and less failure.
All people who work make mistakes, and overloaded workers make more. The difference is that experienced people recognize their mistakes sooner, and usually have a better chance to fix them.
Children make different mistakes, I don't necessarily know about fewer. But if that is a fact, then they make fewer mistakes because they don't have to unlearn the rules of a different language. They just have to learn to communicate, and the brain is a lot more malleable when you are young, so it is easier to pick up when everyone around you is demonstrating. Kids also are more willing to attempt speaking because they aren't worried about making mistakes, and so they learn more quickly. They are also more quickly corrected, with no one worried about offending them, which might also have something to do with it. Humility is powerful.
The best way to avoid grammatical mistakes when speaking English is by learning the rules of the language. The more you understand the rules, the fewer mistakes you will make.
I hope that your mother is not doing this to embarrass you, but to help your sister to learn from your mistakes, and who knows, perhaps you will have an opportunity to learn from your sister's mistakes. Meanwhile, if you feel embarrassed, I can only suggest that in the future you should make fewer mistakes.
Surgeons who grew up playing video games make 37% fewer mistakes.
They make you feel upset, but mistakes are mistakes.
We make mistakes when we are in a hurry.
Entry level over the road drivers start around 35k a year. Experienced company drivers around 60k a year. Owner operators around 200k a year.
You make mistakes because you are human, not the other way around.
Everyone makes mistakes. Making mistakes is simply a part of being human.
That quote means that each time you make a mistake that you learn from them. If your willing to make the mistakes you will learn them then it really isn't a big deal. The earlier you make the mistakes the earlier you will learn the answers.