My favourite animal is cat,so（这样子好点 不用那么多句号的） I have a cat.Her name is MiMi.She comes from China and she lives in my home（用house更确切 另外she comes form China你想表达怎样的意思呢）.She is very small.She has two eyes ,two ears ,a nose and a mouth.（每只猫都有的 建议删除）My mother always(加一个“总是”好一点） calls her (此处应该用宾格 另外is不需要 call sb.sth 就可以咯）"little baby".MiMi likes to eat fish,but she doesn't eat vagetables(用蔬菜vagetables比较好）.She likes runing and climbing .She is clever.
So she is the favourite with all the family!=>So cats are famous for most family!所以猫对多数家庭来说都是受欢迎的.
如果在原文改的话应该是这样子 但是它让你讲的 我最爱的动物
你的文章里面只讲你的猫猫 没有讲猫这种动物是怎么样的
而且也没有讲明 猫比较明显的一些特征 建议可以重新写写看!