What is the ruling regarding a woman working with a married man in a single office where they are alone most of the time, given her need to work because she is a provider?

The regulations concerning women's work have been previously explained, and it is not permissible for a woman to work in a field that requires committing a forbidden act, such as khalwa (unlawful seclusion) or unlawful intermingling, and so on. The definition of forbidden khalwa is: "a gathering where suspicion is not usually averted." If your meeting in the office is in a public place where suspicion is averted, then it is not considered forbidden khalwa. Whenever it is possible for a woman to find work away from men, it is more preferable and safer for her faith and honor.