My sister and I had a JTWROS brokerage account with our mother in 2024. Our mother died September 2024, so my social was listed on the brokerage issued 1099-DIV. Our mother's accountant claimed the capital gains from this 1099 on her taxes (which is advantageous to us). But actually, only transactions from January thru her passing date should be accounted for in her taxes, right? Do we need to file an amended return for her? How do I account for the 1099 on my tax return AND hers when my social is on the 1099 the IRS received from our broker?
