她把身子挺直。用英语怎么说？

她把身子挺直。

She held herself erect.

she

pron. 她，它；

例句
Her lover walked out on her after she had aborted their child.
她的情人在她打掉胎儿后甩了她。

held

v. 拿（ hold的过去式和过去分词 ），举行，保留；

例句
His car was held up and he was abducted by four gunmen...
他的车遭遇拦劫，随后他被4名持枪歹徒劫持。

herself

pron. （反身代词）她自己，（用以加强语气）她亲自，她本人；

例句
She was old enough to absent herself from the lunch table if she chose...
她长大了，可以自己做主不来吃午餐了。

erect

vt. 使直立，使竖起，建立，创立，安装，[医]使勃起；adj. 直立的，垂直的，（头、手等）朝上举的，直竖的，[医]勃起的；

例句
In China Grace Thompson observed the great variety of loads that were carried by 'slim, erect but muscular Amazons'.
在中国，格雷丝·汤普森看见“苗条、挺直而强健的女人们”携带着各种物品。