Macau SAR is generally a fairly safe destination for solo female travelers. Crime rates, especially serious ones, are relatively low. There are, however, occasional cases of pickpocketing or similar petty crimes, especially in crowded tourist areas. It is generally safe to walk around at night, but it's advisable to be aware of your surroundings and avoid poorly lit or deserted areas. In the casinos, there's good security but be mindful of your belongings due to the crowds. Public transportation is safe and reliable. As always, standard precautions should be observed.