Well, get your refund first and then she'll send you a request to get her fees back- at that point you'll have nothing to lose. By the way, is there a Registered Mail service? That's usually the cheapest way to get a signature and have it delivered safely.
I just checked, and it's an extra $13.27 to send it registered so that the seller has to sign for it (in addition to the $30.63, but then you don't get a tracking number. If I want proof that the seller received the package sent back to me, it's an extra $8.17 on top of that, which would make it approx. $52) Would that be a better option than getting a tracking number? I think they require a signature to release the package when I send it with a tracking number, and the tracking number can be sent directly to PP in case something should go wrong. If I just get the registered/signed for then I'll just get a form that the seller has to sign, that I'll have to scan before I can show it to PP, should that be necessary.
Oy, I'm almost confusing myself here

I asked the seller what about the return shipping fees, we'll see what she says.