Carl passed away five years before his wife Mary. His will created a trust to be funded with $1 million of property. The bank trustee was required to distribute all the trust income quarterly to Mary for the rest of her life. Upon her death, the trust assets were to be distributed to the couple's two children. When Mary passed away, the value of the trust assets had increased to $1.7 million. Will the trust assets be included in Mary's gross estate? Explain why or why not.