我的头发比她的长（用两个句子表达） My cousin is the same age as me .的同义句.

My hair _is__ __longer_ than hers___.
I _have___ __longer__ hair than _she__
My cousin is the same age as me
= I and my cousin are of the same age.
=I am as old as my cousin.
再问： 那么，I have longer hair than she's.是对的吗？如果错，又为什么错了呢？
再答： 你是说:I have longer hair than she has??? My hair _is__ __longer_ than hers___. My hair 与hers 比较, 这是主语比较. I_have___ __longer__ hair than _she__ I 与she 比较, 也是主语比较, 为什么要加has ?