Parent wanted a new bed, complained of aches and pains. Wanted a single bed. The bed was purchased after being taken to the store to try out different beds. She loved it for 2 weeks and then another sibling convinced her that it was not a good idea, so now the parent wants her old bed back.
Having a talk with the sibling may be in order. Let her know that mom is very suggestible (as most elderly people are) and it's better for mom is everyone is supportive and encouraging.
She had to replace 40 yr old garbage disposal. We had that done. Now she calls the plumber 1 yr later and says to bring her old one back. She calls him every month or so. No convincing her she can't have it back.
If anyone says " did you really need that new bed?" --parent will second guess themselves especially if they are already worried about their money or rarely spend on themselves.
Nothing you can do about it but discuss with sib and explain that parent needed it and would they please not comment negatively to parent because the parent is anxious over every little thing and "don't you want mom to be happy and comfortable in their last years?" Mom didn't ask if you needed that new TV or that new Phone?"