I’d like that you kindly explain us when we must use "large" and "big". Her teacher has said them that their meaning is the same.
I understand the meaning of both words but I'm not able to describe it to my daughter.

Can you help me?

Thanks a lot.
There are a lot of words related to size and I'm afraid there is no hard and fast rule as to which to use when. Large and big have the same meaning, but sometimes only one is appropriate for each context, as they 'sound right' with some words but not with others. This is called collocation (words being used in combination).

For example,

He has a large house. He has a big house. Both words collocate just fine with house.

I'd like a large coke please. I'd like a big coke please. Only large works with soft drinks.

That would be a big mistake. That would be a large mistake. Only big works with mistake.

So it is just a case of learning what goes with what. Your meaning will still be clear whichever you use, it just might sound slightly odd, so I wouldn't worry about it too much. In a lot of cases either will be just as appropriate.
I understand "big" as both high & wide, and "large" more like "wide", "encompassing many things".
I'm sure natives will come and help you here.
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Thank you very much for your kind explanation. My daughter and me have understand perfectly their meaning.

Thanks again.
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We also thank you for answer. It is exactly what I try to explain her but I'm not able to.

Thanks again
Spanish girl, it's VERY hard to explain anything to your own children... I know how it is, I wish you well