I think in general I understand what your paragraph means. However, you need to be careful with the punctuation. You use 。 quite often. In Chinese, we use comma if the sentence is not completely finished. Also, most of the time, 但是 shouldn't be followed by 。and instead, it should be a comma.
不但不是客觀can be written 並不客觀.
should be 繼母應怎麼對待她的兩個姐姐<< reminder, 姐姐means sisters; 女兒means daughters.
For the last sentence should be: 而是你懂了多少。