But I want nothing to do with her

A strange situation has arisen. We have a chair that no longer fits anywhere so we put it on Craigslist to make a few bucks and save the planet. ( You know - reduce, reuse, recycle.) The first person to inquire is someone who we really don't want to have anything to do with. It's a teacher who we actually moved our kid out of her classroom because we disagreed with her teaching philosophy. At this point, the transaction is anonymous on our end since this person was responding to an anonymized ad, but we know it's her from the email address. Do we reply? ignore? or wait to see if someone else responds? Is there an ethical dilemma here or just the awkwardness of talking/transacting business with someone you would rather never talk to again?