1. Throughout the whole tortured history of their relationship, Elizabeth was eat up with curiosity about her cousin.

结构剖析：这是一个简单句。主语是 Elizabeth，谓语是was eat up with curiosity about her cousin, Mary。在这个谓语中介词短语 about her cousin做定语修饰curiosity，Mary做cousin的同位语。

句首的Throughout the whole tortured history of their relationship是介词短语，表示时间。在这个介词短语中tortured是过去分词作前置定语，修饰history。

2. Mary trapped in a neurotic beauty contest, interrogating her ambassadors as if they were mirrors on the wall, as to who was the taller, fairer, wittier, the cleverer.

结构剖析：这个句子是一个含有分词的复合句。句子的主干是Mary trapped in a neurotic beauty contest。

其余部分中的interrogating her ambassadors as if they were mirrors on the wall, as to who was the taller, fairer, wittier, the cleverer是现在分词短语做伴随状况状语。

这个现在分词短语中含有一个让步状语从句，有as if引导的——hey were mirrors on the wall。As if的意思是“似乎，好像”，那么它引导的从句只是人的感觉，并非客观现实，因此要使用虚拟语气。文中的谓语were。

此外，as to是属于介词短语，意思是“关于”，这个介词短语修饰分词中的非谓语动词interrogate。句中as to后面跟的是宾语从句：who was the taller, fairer, wittier, the cleverer。

3. Elizabeth may have won for brains, but from the few pictures we have of her, Mary, with her heart-shaped face, heavy eyelids and creamy complexion, evidently had the stuff to reduce grown men to warm puddles on the floor.

结构剖析：这个句子是有并列连词but连接的2个并列分句。一个是：Elizabeth may have won for brains；另一个是：from the few pictures we have of her, Mary, with her heart-shaped face, heavy eyelids and creamy complexion, evidently had the stuff to reduce grown men to warm puddles on the floor。

第一个分句中使用了情态动词的虚拟语气，谓语结构是may have won这个表示对过去事情不是很肯定的猜测。

第二个分句中的 with her heart-shaped face, heavy eyelids and creamy complexion这个介词短语做定语，修饰主语Mary，介词with在这里的意思是“具有”。分句中的谓语是had the stuff to reduce grown men to warm puddles on the floor。这个谓语中有个动词不定式修饰名词stuff。