最后一句有错误. 这句话现在是说她的教育程度不高,因为她知道知识的重要性.逻辑不通. 应该是She has vey little school education but she knows that knowledge is of great importance. 注:只能用great importance或者greatly important.
My Mother is a village woman aged fifty.She has very little school education,for which she knows that knowledge is of greatly importance. 应该这for 后面加上which,构成定语从句,先行词是前面整句“She has very little school education”。这样语法上和意思上就都正确了。