1099R, Estate account

If my sister passed and I am her only beneficiary and the executor of her estate, how do I handle her tax return. I have already filed mine and after reading some of these post it sounds like I may have to amend mine.  I opened up an estate account with EIN for my deceased sister.

 

I received one 1099R (50K) with my name and ss because I was her beneficiary. I filed that one on my return.

 

I received her SS statement and another 1099R with her SS and I assume that goes on her final return.

 

I received a 1099R (26k) that has estate and beneficiary (I am the only one) and the EIN on it. 

 

1, What return do I file this on? My personal? which is going to be an amendment if so, or her final 1040

Or do I have to file a tax return for an estate?

 

2. If I have to do an estate account with only 26K 1099r to claim, do I have to create a k1 and file that on my personal one?

 

3.  And can I deduct any expenses I paid out of it?

 

Thank you so much to whoever can help me with this complex question.