Maybe the fact of the JTWROS is what is confusing the issue.
While state law governing property ownership varies by jurisdiction, there are a number of principles generally applicable to a tenancy by the entirety. Tenancy by the entirety is a form of property ownership, including personal property in some jurisdictions, available only to a husband and wife as a marital unit. A key feature of the tenancy is the right of survivorship–the surviving spouse becomes the fee simple owner of the property upon the death of the other spouse. The tenancy also is terminated by the transfer of the property or upon the spouses’ divorce. JTWROS
Also:
Include one-half of the value of a qualified joint interest in the decedent's gross estate. It doesn't matter how much each spouse contributed to the purchase price. Also, it doesn't matter which spouse dies first.
A qualified joint interest is any interest in property held by married individuals as either of the following.
This is a gift. Your aunt even said so: "In fact, the aunt wrote 'Gift' on the Grant Deed."
