Depending on the tournament/size you will typically find ages that differ from the guys. This is to get more matches.

The nationally recognized weights can be found here: http://content.themat.com/forms/Weights.pdf

For local tournaments I've seen them use:
Elementary, Middle School, High School

2014 USA Folkstyle Nationals Used:
Div 1 05-07, Div 2 02-04, Schoolgirl 00-01, Cadet 98-99, Junior

Also, most tournaments utilize block weights to get optimized bracket sizes.