Dependent care fsa married filing separately

My wife and I file Married Filing Separately because she is on income based repayment for student loans. I understand the for that filing status, we both (separately) can contribute a maximum of $2,500 ($5,000 total) into a Dependent Care FSA account. We have two kids; ages 2 and 1, whom my wife claims on her taxes. We send them both to the same babysitter who provide us with her information for tax purposes. 

1) Can we both use the "end of year receipt" with how much we paid to get reimbursement for each of our DCFSA accounts? The total will significantly exceed the maximum $5,000 per household ($2,500 separately). I read that you can only use your dependent care expenses one time when requesting reimbursement.

2) When we file, do we need to do anything differently to have the $2,500 accepted for filing? Meaning, because my wife claims both our kids, but I save for dependent care also, what do I need to do so we can take advantage of the money I saved and not have that added back into taxable income for me?