Yes. You should let someone to help your kid.

Here is our experience.  My son's high school has college councelling department, the ratio is about 100 kids per one councellor.  Their jobs are help you to get to the colleges that will fit you.  My son went his counsellor for helping with his essay.  There is also another teacher who wrote the recommandation letter for my son, he helped with the essay along with the college counsellor as well.  

On top of the school college councelling, we have also hired an outside advisor on college admission to help with the whole process.

Bottomline, the answer is Yes, you need to let someone with the experience of college admission to help with your kid's essay.