Shiv,

Here is a chart that shows a Junior Golf Association's tournament distances and pars.

Age Group Holes Tees Played or Yardage
Girls 08 - 10 9 Holes Par 5 - 250, Par 4 - 175, Par 3 - Ladies Tee
Girls 11 - 12 9 Holes Par 5 - 300, Par 4 - 200, Par 3 - Ladies Tee
Girls 13 - 14 9 Holes Ladies Tee - "B" Div. - 9 holes
Girls 15 - 18 18 Holes Ladies Tee - "B" Div. - 9 holes

Boys 08 - 10 9 Holes Par 5 - 250, Par 4 - 175, Par 3 - Ladies Tee
Boys 11 - 12 9 Holes Ladies Tee
Boys 13 - 14 18 Holes Men's Tee - 6,000 - 6,400 - "B" Div. - 9 holes
Boys 15 - 18 18 Holes Men's Tee - 6,200 - 6,500 - "B" Div. - 9 holes

Based on what you said, and you only being 7:

A par 5 being a max of 250, and you drive it 140. That leaves you 110 in. Your 3W goes 120, so you would even make it to the back pin placement!

Looks like you are ahead of the game...keep it up!