But, really, you shouldn't be babysitting until you're at least 14. People make mistakes, even if you are responsible you are still young and young people do stupid things.
I'm extremely responsable, and I'm relied on by a lot of people. But yet, I still was irresponsible enough to let my bird die in the way she did. Anyone could have made the mistake I did. But younger people are more prone to those kinds of things because we are young.