The transfer to an inherited IRA for the benefit of the estate can only be done by a nonreportable transfer, so there should be no Form 1099-R for that transaction.
As for the distribution from the inherited IRA paid to the estate, the estate should receive a code-4 Form 1099-R reporting the distribution (sent to you as administrator of the estate). That Form 1099-R should have the EIN of the estate, not your SSN. This will be reportable on Form 1041 line 8 as Other Income. The amount that is distributed to you from the estate after the estate's debts are paid will be income passed through to you on Schedule K-1 (box 5 - Other Portfolio and Nonbusiness Income) as the estate's beneficiary to be included in your income on your individual tax return. The estate will receive a Distributable Net Income deduction for the portion that passes through to you but not for the portion that is used to pay the debts of the estate. The portion that is used to pay the estate's debts will be taxed at the likely higher estate income tax rate.
(Although probably not the case, if your sister had basis in nondeductible traditional IRA contributions, the taxable amount of the distribution is reduced by the amount of the basis.)
