关于英语句子中的标点符号如例句：“If they did,they often were not taught much

关于英语句子中的标点符号
如例句：“If they did,they often were not taught much except the French language,how to sew clothing,and music.”
and music前面这个逗号可以省略吗?说明理由.
还有“Through her lifelong work for education she became one of the most famous women in 19th century America.” she became 前需要逗号吗？
She believed that women were teachers both in the home and in the classroom.both前需不需要逗号
And,she believed that efforts to better educate young women also served God.and 后的逗号可不可以省