Assume the total life-time estate tax exemption limit is $12 million. A married man, upon his passing, leaves $3 million of his separate property to his wife, and the other $5.7 million to his other heirs. Later that same year, his wife passes and leaves an estate with a net worth of $26.9 million. How much of her estate is subject to estate taxes? Assume she has not earlier made any gifts in excess of the annual tax-free limit, and that the estate incurs negligible funeral and administrative expenses. Enter answer in millions (i.e. no need to type in all the zeros)