I am looking for some general guidance here on expenses.  Just looking for some clarity is all.

Quick background:
We currently have shared parenting time (50/50).  I make a little over two times what she makes on income.  We ended up having to go to court and it was decided by the court that she would receive maintenance of $A and she would pay me child support amount $B (B = 1/2 * A).  We have no wording in our divorce decree of what are / aren't direct expenses and indirect expenses.   

Moving up to now:
I have been taking care of all daycare and school expenses, extra curricular activities (sports, etc.), clothing, haircuts, insurance, etc.  Everything has been paid on time and without issue and ultimately that isn't the issue here.  Clothes and toys have been going back and forth without issue.     

The issues are:
1. She believes that I should be paying for items for the children that she does with them on her time (such as take them to movies, pay for items when they go on vacation with her, when the go out to eat with her, etc.).  These are generally minor expenses and more just entertainment than anything else.  Is this part of what is considered "direct expenses"?  My definition of how I view it says no but her definition of how she views it says yes.     

2. She feels she should not have to ask "permission" to purchase something for the kids and that I should reimburse her for the items.  I am not asking for permission, but I would like to know what she is planning on doing so that we are on the same page and I know what to expect for expenses coming in.  This seems like a situation that could open the flood gates to other issues such as her deciding to take the kids out to eat several times a week and go to the movies and then just send me the bill for these items.  My definition is if I am in charge of the monetary circumstances for the kids, I should have some say in what is spend on the kids.  Add in that other than a situation where their lives were in danger, I don't see why she would believe it is okay to basically have a blank check for her expenses for the kids.  Am I missing something? 

Thank you for advice.