Yeah those can be difficult conversations to have with a doctor. I usually start by asking the purpose and goal of a drug and if still makes sense. Or, just ask since the ANC is good, what's the purpose of the anti-biotic and anti-fungal. There should be a good reason to keep it on board. Especially since anti-biotic use can lead to intestinal infections like C-Diff.
There's no harm is discussing that you've been talking to other SAA patients in recovery for support and asking him to explain why your mom's post ATG treatment is different from others regarding the prednisone and other drugs. Quality of life is important and it's also important for you to feel you have a voice in the treatment. If he is offended, then maybe it's an indication to find another doctor for a second opinion.
We were lucky in that our local hematologist was open to hearing our concerns and did not dismiss us.
When John was hospitalized and counts were not improving I researched all the drugs he was on and found that one of the "special' antibiotics can cause AA. They blew me off during rounds but the nurse researched it and the next day they took him off it. We were already going on 80 days without a white count and getting very frustrated. They then said that pretty much all anti-biotics can suppress the bone marrow. A comforting thought.
Here's a paper by Neil Young on how he treats SAA.
https://ashpublications.org/blood/ar...plastic-anemia
Last two thoughts: 1) Not knowing her platelet transfusions threshold but if her platelets are holding 10K or 15K without any bleeding you may want to consider stopping platelet transfusion. John lowered his threshold to 8K. Some go as low as 5K.
2) I think you have time on the iron overload. Unless there was an issue of high iron before she got sick, you most likely have leeway on when to address this.
Hope this helps. It's not easy to navigate all of this stuff. You mom is lucky to have you help her.