Our 23 year old daughter married June 19,2010. She meets all the criteria for us claiming her as a dependent except her wedding date is not quite 6 months at our home. How persnickety will the IRS be since she is about 11 days short of the 6 month mark? Thank you for your time.

Six months is just that. 11 days, 23 1/2 days, where does it end. They may never know her wedding date, but have you asked her about this? I would imagine that she and her husband will be filing a joint return and claiming themselves. Time to let her and her deduction go, sorry.

Thank you for such a quick response!

Your daughter can still be your dependent as your Qualifying Relative. It is not required that she lived with you. You must provide more than half of her support for 2010 and she did not earn more than $3650 in 2010. Another requirement:
Joint return test. You can’t claim a married person as dependent if he or she files a joint return except that the joint return is only a claim for refund and no tax liability would exist for either spouse on separate returns. Dependent -- Qualifying Child and Qualifying Relative Your U.S. Tax Return: Requirements for claiming a dependent