I am sorry about the death of your daughter. I suggest you file an extension request (Form 4868) on her behalf. You can file the extension request electronically. The extension will give you more time to get more complete financial information. Then, file a return based on the best information you have.
See IRS Publication 559 for more information, at https://www.irs.gov/publications/p559#en_US_2020_publink[phone number removed]
