Why doesn't my friend's breath smell?

We're both 15, if that makes a difference. I have braces, and I brush my teeth 2-3 times a day. My friend, (doesn't have braces) brushes her teeth...... 0 times a day. Never. Her mom even threw out her toothbrush because she never uses it. Her teeth are as yellow as they can get, yet... her breath never smells! I'll eat one thing, and boom, smelly. But she can eat anything, any time, and never gets bad breath. WHAT IS THIS?!