What do you mean, she is bidding on it? This is not something that occurs on Etsy so I'm confused. She can certainly contact you and ask for whatever she wants, but there is no bidding setup like on Ebay.
I had a similar convo this week. I responded that I did not offer discounts but did offer coupon codes occasionally. I told her I could convo her when I did have an active coupon code. This was me just being polite. I used to sell on eBay and got really tired of the lowball offers.
Yes Sally she emailed me and told me she'd be happy to pay 10.00 dollars in place of the 15.00 i am asking. I did tell her that my prices were none negotiable but it was just a first for me being privately messaged with this sort of bidding offer. I just thought I'd see what other people thought and if they had experienced anything similar.
Yes I too do that here in Holland Maryanne and the bidding gets tiresome especially when everyone wants something for nothing. :'(