It sounds like these people are desperate and pulling out all the stops to get some money, even if it's just a shot in the dark.

With an annuity, a death beneficiary will be specified on forms provided by the annuity company. These forms probably have been properly executed, signed, and dated. Then, to leave no doubt as to the intent, a will must have been drafted, repeating the name of the annuity beneficiary.

An annuity is a private contract. A person who purchases the annuity always will be asked to designate a beneficiary for the remainder of the fund in the event of his or her death. I'm sure this was done properly.

Anyone claiming a right to an estate has to do so by claiming that there was no will, and that that person had a right to a part of the estate as a child or spouse of the decedent.

Things sound pretty far fetched here, with an ex wife, an estranged brother, and both an annuity contract and a will that make it pretty clear who is to get what in the event of death. Claim as they may, they'll get nowhere in court.