The phrase "I don't know how she does it" expresses amazement or admiration for someone's ability to manage or juggle multiple demanding tasks or responsibilities, often used when referring to someone handling a busy or challenging life situation, like balancing work and family life.

Additionally, "I Don't Know How She Does It" is the title of a 2011 American comedy film starring Sarah Jessica Parker, about a working mother trying to manage her career, family, and personal life.

If the phrase is used conversationally, it usually means the speaker is impressed or puzzled by how a woman manages to cope with her responsibilities so effectively.