I just accepted a request from someone who had an interesting RC that I don't think is going to give them the results they are hoping for. The first part is fine, she doesn't want books from a smoking home. The second part says

I would prefer only to mail books within the USA.

How is that going to work? You only see this when she requests a book not when you request a book from her. At least that is my understanding. Should I pm her and let her know that they only people who are seeing that she wants only to mail books in the USA are people who are sending her books and that only USA is allowed currently except for APO addresses which are technically USA anyway although I know some people don't like to send to them.

I wonder if she's thinking PBS is like that other book swapping site?

PBS is a US only site, so she doesn't need that in her RCs at all, even if she wasn't also showing it to the wrong people anyway. There is no way to order a book internationally here even if you wanted to. You would not be able to put in the address.

Yes, I would go ahead and PM her.

I just sent what I hope is a nicely worded post letting her know that her RC isn't reaching her target audience and that she might wish to change it.