I am so sorry for your loss.
You need to file her form 1040 including her date of death and a state tax return (if she lived in a state with income tax).
For the estate, you need to file form 1041.
For more information about filing the taxes of deceased taxpayers, follow these links:
Form 1041 Instructions
IRS
on Deceased Taxpayer
E-file Deceased Tax Returns
https://turbotax.intuit.com/tax-tips/family/death-in-the-family/L5albFXM4
