I wore the kilt out last night to a friend's birthday party, and and ran into an aquantaince who wasn't familiar with the kilt or its cultural background. He was curious, asked a lot of questions, and ended up thinking it was sort of neat.

Your coworker's spouse could have been gently told that without these sort of encounters and this sort of education, her progenitors would just be regarded as "freaks in skirts." By wearing the kilt out and responding to questions about it, you are keeping her cultural traditions alive.

(It may be that she doesn't much care for that tradition.)