California Child Support. What expenses are covered?

I've done the income calculation and it says I should be paying close to $500 per month for child support to my ex. I'm paying $650 based on court order over 10 years ago, when my income was slightly higher. With that aside, I'm okay paying the $650 but exactly what expenses are being covered and which ones don't need to be? on top of the $650 I'm paying the following: 1. 50% Medical Insurance (she's paying all of the the Dental Insurance $24) 2. 50% Sports activities 3. 50% Braces 4. 50% Medical copay expenses outside of health insurance. She wants me to pay extra for: 1. 50% of school lunch money 2. 50% of clothing (I buy him clothes here and there as well) 3. 50% of the Dental Insurance. So again does anyone know if I'm over paying or if I should be paying 50% of the additions she wants me to pay?
--------------------
I'm in So-Cal. And, I've been through a divorce with kids too. If you really think your income has decreased since your last child support order, then you may want to consider requesting a reduction in the child support. But, if her income has decreased too, that may have an effect. The first child is always 25% of the father's income and then they put the mom's income in the disso-master. And then of course, it's based on the percentage of time each parent has with the child. My take on those 3 extra items the ex is asking for, I'd say "no" to the lunch money and clothes. That's what the child support is for. And the dental insurance - probably. So, if you really think that you are going to get it lowered, then try for it. You might be able to get some free help. I know my court has a "Family Court Facilitator". This person only deals with child support issues and it's free advise and free forms that need to be completed and filed. You'd pay the filing and serving of the papers, but at least you won't need a lawyer. See if your court has one of those and then make an appointment and discuss with that Facilitator. They probably can do your calcs for you and see if you have a motion to file. Good luck.
Source