preparing taxes for a deceased relative

[klcci]

My mother passed away in 2023 I just realized that I should have filed her taxes for 2023, but I didn't. If I file her taxes this year do you think that there will be penalties for not filing them? Also, in the year 2024 I was paying her mortgage until December when I took over the loan. The interest on the mortgage was accounted to her. Will I have to also do a tax return for her for  2024 as well? Are there any special forms that I will need to file in addition to the 1040?

[MaryK4]

Your mother's final return will be the 2023 (the year of her death).  Because you filed late, there may be penalties for filing late if taxes were owed.  If she has an estate, the estate might be able to claim the mortgage interest paid, but with no income, the deduction would be moot.