So, round these parts, everybody has to wear a shirt on a construction site.......no exceptions and either a hi-vis vest or hi-vis t-shirt.
I mean, i understand where she's coming from but on most construction sites, a shirt is mandatory, unless it's a scumbag site, then anything goes, i suppose.
Back to your question........on my site, she would be kicked off, but anyone not wearing a shirt would be kicked off and if they had an issue with it, then straight to HR.