How do I teach Siri to spell my wife's name correctly in texts?

When I use Siri to dictate text messages she always spells my wife's name "Aaron" when her name is actually Erin. It's frustrating that no matter how many times it select Aaron and change it to Erin, she never incorporates that info in the future. I've tried teaching her to pronounce my wife's name via asking her "Who is my wife?" But this only seems to teach her what contact corresponds to "my wife". That also does nothing to change that she always spells Aaron when dictating anything to her. It would be great to discover a solution.