Wouldn't agree with her covering anything she wouldn't while in the USA.
I couldn't give a shit about some of these ridiculous traditions or expectations when foreigners travel to countries like these.

Muslim traditions should be for Muslim people end of story.
I might bow to some minor traditions in other countries ....for example how people greet other people such as in Japan or other Asian countries..........but I don't agree with traditions where for example women are expected to cover up hair,faces,body.

If she wants to do it fair enough...if she doesn't want to, fair play to her.
She makes the choice,not them.