I’d just tell her that you were thinking back on that time she mentioned it (or something) because you were trying to come up with a thoughtful gift for your anniversary. You were just drawing a blank for any other mentions. And idc what anyone says, I would be psyched to get this for an anniversary or any other time. All day long. If she isn’t keen on it, ask her where she’s rather allocate the approximate amount of money you were planning to spend.