It is very difficult to get an answer from my mother what she wants. She won't tell me what she wants to eat but complains about what I bring her. She won't tell me if the new mattress is better. We got her a mattress to prevent bed sores. She complained about the mattress that it was not working. We had the company come and check it. They found nothing wrong but replaced the motor. Within two days she complained again about the mattress. We had the company come out again and they found nothing wrong with the mattress. I told them just please replace the mattress. The next morning I asked her how she liked the mattress. She would not commit and said how should I know. This is so frustrating because she answers this way about everything. She is in her early 90s, is on pain and depression medication. She can never give me a straight answer. I usually have the aides try to find out what she wants or needs and they also have a hard time figuring things out.
When you give her a choice, give her two options AT MOST. It makes it much easier to make a choice this way.
Try tweaking around the edges. Add a foam pad to the bed. Remove the foam pad. Add a 2nd foam pad. Add an extra pillow, etc.
Recognize that you are probably not going to satisfy her. What she probably wants is to be young and healthy. And learn to say, "I'm sorry Mom that you're not happy. It must be really hard to be 90+ years old.