Koh Samui is generally a safe destination for solo female travelers. However, like any popular tourist destination, there are occurrences of petty crimes such as pickpocketing and bag snatching particularly in crowded places such as markets or at night parties. It's always important to keep an eye on your belongings, avoid displaying valuable items in public, and be aware of your surroundings. Overall, beyond typical travel vigilance, you can explore and enjoy Koh Samui with a low likelihood of encountering such issues.