I am sorry for your loss.
In order to file a return for the deceased, you will need to create another account as one is necessary to file another individual tax return in TurboTax Online, but you can use your email address to create the other account, you will just choose a different User ID and password. For instructions on how to do so, please see the following TurboTax FAQ:
https://ttlc.intuit.com/replies/3288574
Please see the following TurboTax FAQ for more information on filing a decedent return:
https://ttlc.intuit.com/replies/3300219
