Howard's will devises his entire probate estate in trust for the benefit of his wife, Constance. The trust contains the following provisions:

During the lifetime of my wife, the Trustee shall distribute the net income to my wife on a regular, but not less frequent than annual, basis. Additionally the Trustee, n its sole discretion, may distribute as much of the trust principal to my wife as the Trustee determines necessary or appropriate for her health, support in her accustomed manner of living, or maintenance. Upon my wife's death, the trust assets shall be distributed to my issue then living, by representation.

Howard died with a gross estate in the $$16$m range, without having used any portion of his unified credit during his lifetime. Constance has approximately $$20$m of assets in her individual name.

Does the devise in favor of Constance qualify for the marital deduction? What advice do you have for Howard's executor?