Religion or not, if she doesn't want to shake someone's hand why should she? So dumb. Like if I don't want to touch your hand and its bothering you so much that you're taking offense to it then maybe the problem is on you, not me.
And not to defend her religion in any way, but if we're supposed to be respectful of people's customs (i.e. shaking hands) then shouldn't we also be respectful of other people's religions?
