Is there a law against leaving a 14 year old home alone with a 3 year old and a 1 year old for 6 and a half hours?
You are not going to get out of babysitting your siblings legally, so bear it with some grace.
Nope, here you are legal to babysit when you are 12. When I was 14 I took care of three little kids for 3 days in a row, and watched kids all day during the summer and made sure supper was on the table when the mom got home from work.