Deceased mom several years behind on tax filings

My mother passed away in December and I found out about a month later that she had not filed her taxes for three years, putting her four years behind if you include this year’s filing. I have a brother with special needs who has a trust that requires filing taxes every year and she had not filed those as well. Part of the problem was that my stepdad got really sick and she became a caregiver back in 2022 and he had been the one to handle the taxes prior to that. He passed away in 2024 and I think she felt too overwhelmed to get caught up. She had an accountant who I was able to connect with and at the time he was very grateful to hear from me because he had been bugging her for years to get him what he needed to get her taxes filed. He assured me back in January that it would take time, but he would get the past due taxes filed, and then file for 2025 for both my mom and my brother’s trust.

Fast-forward to May and nothing has happened yet. I have contacted him several times and he tells me he is working on it but that it is tricky since my stepdad would have been part of the taxes for 2022, 2023 and 2024. I am the executor of my mom’s estate and I’m starting to freak out that nothing’s been done and I don’t even know where to start because she left very little paperwork behind. The situation is further complicated by the fact that I live in North Carolina and she was in Texas and that’s where her accountant is so it’s not like I can just drop by and bother him in person.

I’m completely overwhelmed by this situation and don’t know what to do at this point. I feel like I’m at the mercy of the accountant getting this work done but every time I call, he assures me that they’re almost done and then I never hear anything.