He had emergency custody from January until about summer, courts gave her back full custody with the agreement of him having her during the summers. So initially he had her from Jan. To September and even since then, she has only cared to take her a few times a month so he is still supporting her mostly. Mind you, she lives off the government while he is paying child support and didn't work the whole yr of 17. How is she able to claim her! Someone please help this isn't right!
To begin with, the IRS does not care about court orders or agreements when determining dependency status. All that matters is the tax law.
While the rules for claiming a dependent can be complex, here are the basic requirements to be able to claim a qualifying child as a dependent - you can see more information at these links Rules for Claiming a Dependent on Your Tax Return and IRS Publication 501 (starts at page 11).