Halloween

This Is Like So Cool!
HALLOWEEN~!!!!!!!!
Halloween is like the most awesome holiday ever, well... one of them.
Here is a contest thing...

There are two children. Brother and sister. One day the brother says, "sis, you know what? If you take 2 years away from my age and give them to you you'd be twice as old as me!"

The sister says, "How 'bout we add one more on top of that? Then I'll be 3 times your age!"

How old is each sibling using the clue that follows:
Each sibling was born in the same year.