What is the ruling regarding the mahram or the absence of khalwa within city limits? And is a six or seven-year-old girl considered to negate khalwa with a driver if she is discerning?

It is permissible for a woman to ride with a non-mahram driver in the presence of a discerning child (from 6-7 years old and above), as this negates unlawful khalwa (private seclusion), provided there is no fear of fitna (temptation or discord). This is allowed on populated roads and within cities, with the woman sitting in the back seat away from the driver. However, outside of cities or in unsafe areas, it is not permissible. A woman should remain in her home and not go out unless there is a legitimate need.