In 2011 I had no income, but I will have income for 2012. My daughter and I lived on an inheritance from my mother we received in 2010. My ex-wife wants to claim my daughter as a dependent, but I supplied the vast majority of support for her, and she lives with me. Will allowing my ex-wife to claim her endanger my status in the future, or even be illegal? Cam my mother's estate claim 'head of household', or even me as a dependent?

1. The custodial parent has the right to claim the child as a dependent, but you can sign over your right to your ex by providing her with signed IRS form 8332. She then attaches that form to her return. This will not endanger your ability to claim your daughter on your 2012 tax return.

2. Since your mother died in 2010 it would be unusal (but not unheard of) for her estate to have to file an income tax return for 2011. But if it does - the estate income tax form 1041 does NOT have any provision for filing status or claiming dependents. So no - your mother's estate can not file as Head of Household. I would advise that if you are handling your mother's estate and are filing an estate income tax return you engage a professional knowledgeable in handling estate filings to help you.