I cooked salmon and my mom is going to be late for dinner what should I do with the salmon?

We often cook more than we are going to eat and repurpose it in many ways after.

Unless she dislikes room temperature food, I'd just serve it when she gets home.

I know this comes late but we actually prefer cold or room temperature and I often make a salmon platter with seasonal vegetables similar to this:
https://food52.com/recipes/11679-spring-vegetable-and-salmon-nicoise-platter
You could also make salmon pasta or chowder...just add your cooked salmon at the very end.