@DavidP I think it's correct, even though there are many valid ways for this I think. Maybe adding the toilets as a node in the building would make them more visible (and would be valid as well)? By the way maybe an "tourism=picnic_site" / "shelter_type=picnic_shelter" would be appropriate with the "amenity=shelter" too?

Is this in Oregon?

i would add the toilets as separate notes, at least that's the most fast forward way to do it

@DavidP how have you added the toilett? Is there an OSM Link?