The payment and Form 1099-R should have been issued to your Aunt's estate, not to you, and is reportable on an estate income tax return, Form 1041. The estate can then pass the income through to the estate beneficiaries as Distributable Net Income on Schedules K-1 (Form 1041).
If the money was (inappropriately) paid to you and the annuity company will not correct the Form 1099-R to show that you received no distribution and issue a Form 1099-R to the estate, you'll need to nominee the income to the estate (not to your siblings) using the process that fanfare indicated. You'll then deposit the funds into the estate account, apply it to any unpaid estate expenses, the distribute the rest to the estate beneficiaries.
