I assume you mean ‘does not form part of the estate of the ex-husband’?
If this is a joint lives, first death policy and was untouched by the financial arrangements following divorce, then the proceeds do belong to the ex-wife and all she has to do is to show a death certificate to receive those proceeds.
It is not common for a trust to be put in place for these joint lives policies unless both spouses die in short order (usually within 30 days).
Jill MacMahon
Thackray Williams LLP