There are next to none where I live, but our local paper has just recently hired someone with an arab name who is writing for them and I am certainly curious. We are a very small city in northeastern upstate NY. In Albany, where my twin daughters live with their families, there are many Muslims. I was down there last week and some girl wrote a letter to the editor about Muslim girls being made fun of because they wore hijab. Of course, Albany also saw a major arrest last year of terrorist abettors.
I'm sure that your girls are well aware of the dangers, and are keeping their eyes open. Those kinds of letters are an opening salvo for them. I don't believe anyone would make fun of girls wearing hijab. I'd take notice and all, but I certainly wouldn't be rude. Be vigilant, especially now that we're getting all kinds of new found citizens.