So sorry to hear how they treated your mom. We found it's best to avoid the ER at all costs. But if you can't, it can help to have a letter/transfusion orders from her doctor that specifically state the transfusion requirements. Also the actual studies, if you can find them, about the age of blood products. Age does matter and it makes sense that those getting red cell for blood disorders should have red cells that will last the longest versus someone who has a one-time event requiring blood. I would not hesitate to report the incident to the administrator of the hospital.
Not certain of your mom's routine ( how often she gets a CBC) but it may be a good idea if you haven't already, set up some transfusion thresholds so you can avoid the ER. John, along with his doctor, decided when he would need transfusion and set thresholds. His threshold for red cells was when his HGB dropped to 8 - 8.3 range and his platelets at 8K. All his products were to be cmv negative & irradiated. His platelets were to be single donor. For your mom, dropping to 6.5 sounds like it's too low for her so maybe a HGB threshold of 7 or 7.5 would be doable. This way you have time to set up the appointment with transfusion center. I know you are worried about iron overload but at this point, it's not a big issue and you can discuss using an iron chelator at some later point to keep it in check. You may want to ask the doc to request red cells no older than X on the orders.
Lastly, I am a big believer in 2nd and 3rd opinions. Experience with the disease and treatment is a must. All doctors and BMT centers have their biases towards their protocols. Nothing wrong with that but you don't always hear about all the treatment options available. They tend to stick what they know/do. It helps when you have confidence in your healthcare team and choices.
Marlene, wife to John DX w/SAA April 2002, Stable partial remission; Treated with High Dose Cytoxan, Johns Hopkins, June 2002. Final phlebotomy 11/2016. As of January 2017, FE is 233, HGB 11.7, WBC 5.1/ANC 4.0, Plts 146K.