楼主……直说一句话……你这篇文章的最大毛病就是太过Chinglish……就是完全以中文的思维来写的这篇文章……
1.第二段开头不要用As soon as,直接用When即可；后面的for ten months time可以把time去了；our hearts 【are】 full of……
2.第三段：第一句改为：our daughter is a healthy ,optimistic,and happy girl;Almost all people 【who contacts with her】【would like】her……(其实这句完全不用那个从句,直接说Many people around like her very much.就行了)；之后的那句话：……she (will be删掉)is a (good删掉,和之后的俩词意思有重复)smart and 【lovely】(cute和smart都有敏锐聪明的意思) girl.
3.第四段：Our daughter 【is】( 这个地方最好不要用省略写法);we let her to learn 【to play the piano】……；When she was 12 （years old去掉,之前已经有了）……；the second 【price】……；
4.第五段：我个人认为这段完全可以不要.刚刚已经夸了那么半天您女儿的钢琴怎么好,现在冒出来了这么一段,完全是煞风景……
5.第六段：She 【has】many……（这个错误错了好几处,不是have是has,第三人称单数,其余的就自己改了吧）；students often have difficulty or problem to discuss with her.这句话改为：when her classmates have difficulties,they often want to discuss with her.(注意单复数形式)；……often very accurate to say that the substance of the issue这句改成：……can often point out the key of issues.
6.When she heard a song which she like it,she always find the song when she comeback home and downlord it in her MP3 player.这句话问题严重……应该是：When she 【hears】a song which she【likes】,she always 【likes to download it in her MP3 when she comes back home】其实……这句话我也觉得写法不当.如果想要表现你的女儿爱好音乐的话完全可以举其他例子,这个例子完全不具典型性.还有就是……楼主啊……注意第三人称单数形式啊……您女儿是第三人称,一定是用三单现的形式啊!
7.……she always 【does】 some housework,【and】 also 【solves】 problem with 【us】.还有：……she gives us a word on a relaxed and harmonious.这里relaxed 和harmonious都是形容词,所以在此之后需要加一个名词,否则句子结构残缺.
8.Our daughter likes small animals.Squirrels and other small kitten puppy.这应该连成一句话.并且kitten 和puppy已经有“小”的意思了,就不需要再在前面加一个small了.所以这句话应该改成：Our daughter likes small animals such as squirrels,kitten and puppy.之后：【Her grandma】 has three cats and one dog,【and she likes them very much,specially a small black cat.】Each time 【we go】to see grandma……
9.Our daughter 【is】 not so fastidious 【about】【food】.紧接着的后面一句不能用as long as这个句型,完全是莫名其妙.应该改成if the food is good for health,she does not refuse it.楼主这里还要注意一个问题：这文章的时态太混乱了.要么都是用现在时,要么都用过去式,不要一会儿过去一会儿现在的,这样理解起来很恼火……最后的一句完全也可以省掉,因为你在这里写这么一句话和之前的她不挑食没有任何关系.
10.头句同上,不要省写；To take part……这句话不要重起新句,直接可以连着上面一句写.There is no strangeness for her.这句话你想要表达的意思我知道,但是感觉这个英文句子有点别扭,应该换一下（我一时也想不出更好的表达方法,不好意思……）get along well是个固定搭配,不用在中间加一个very；之后的become a member of your happy family也完全可以不要,因为你的意思在前一句已经表达到位了；之后的manage要改成treat,without的那部分可以省掉；She will be very happy with you.应改为：And we're sure that she will be very happy to live with you all.最后一句We express deep gratitude again.应该提行重起一段,并且在express之后再加一个our.
大致就这么些问题.不过楼主还应该再继续慢慢斟酌一下你的语句表达,还是觉得太过中文化,而不是在写英文.
希望这些修改能对你有帮助.