Torreon is moderately safe for solo female travelers. Crime rates are average, but they can increase in certain areas, especially at night. It's highly recommended to stay vigilant, avoid isolated areas, and not to carry a lot of money or valuable items. Public transportation should be used cautiously and decisions should be made through well-informed judgement. It would be beneficial to know some Spanish to better communicate and navigate. Lots of locals are helpful, and the city has much to offer, but it’s still advised to be cautious and aware.