My understanding is that for the subject matter of a trust devise not to fall into residue on the termination of the trust, the gift into trust must be exhaustive. Usually this will specifically include the identity of the beneficiary entitled on the termination. If that gift then fails, for whatever reason, the trust fund passes as on an intestacy.
Where the gift into trust is not exhaustive, I believe that upon termination of the trust the trust fund falls into residue.
As the wording of the gift into trust appears only to deal with the widower’s income entitlement, I am not convinced that it is an exhaustive gift and, like Simon, am inclined to the view that it falls into residue when the widower’s interest ceases.
I suggest it might be appropriate to obtain the opinion of Chancery counsel, which can then be shared with the potential beneficiaries. If they cannot agree on the interpretation, this will likely bring forward the discussion and allow matters to be resolved sooner, rather than be allowed to fester.