She had shared responsibility for her brother since girlhood.是什么意思？

She had shared responsibility for her brother since girlhood.

她还是个小姑娘的时候就分担起照顾弟弟的责任。

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。

had

v. 有（ have的过去式和过去分词 ），（亲属关系中）接受，拿，买到；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

shared

adj. 共享的，共用的；

例句
She tried to ensure her affection was equally shared among all three children.
她尽力确保三个孩子从自己这里分享到同等的爱。

responsibility

n. 责任，职责，责任感，责任心，负责任；

例句
Many parents simply abdicate all responsibility for their children.
许多父母对孩子简直是完全撒手不管。

for

prep. 为，为了，倾向于，关于，当作；conj. 因为，由于；

例句
I've come looking for a bit of advice.
我特来讨教。

her

pron. (she的宾格)她，(she的所有格)她的，她，指某个国家，（一艘）船；

例句
There was a terrible sadness in her eyes...
她眼神中流露出深深的悲伤。

brother

n. 兄弟，同事，同胞，同志；int. （表示生气或吃惊）我的老兄！；

例句
Julian Lloyd Webber thinks his brother would like the approbation of serious critics...
朱利安·劳埃德·韦伯认为他弟弟希望获得严肃批评家的认可。

since

prep. 从…以来，自从…之后，自从；adv. 以后，此后，后来，（距今几年）以前，（从那时候起几年）以前；conj. 自从…以来，自从…的时候起，既然，因为；

例句
Janet had been abused by her father since she was eleven.
珍妮特从11岁起就遭受父亲虐待。

girlhood

n. 少女时代，少女时期，（总称）少女们；

例句
Her girlhood dream had been to study painting.
少女时期的她曾梦想过学习绘画。