C.O.
B.,
Sorry....this isn't about Military moms or Military wives....you need to know what to wear to a party. A retirement party is just like any other retirement party. The difference? There will be people there in military uniform.
Personally? I would go shopping when I got there. Weather is different in Arizona than Ohio.
She already told you what she was wearing...nice jeans and a nice top. Don't make it complicated. Use the KISS Method - Keep It Simple Silly.