Except for one thing that I don't think anyone has mentioned. This is a common ploy on behalf of owners of real estate to get the highest price for the property w/o appearing openly that that is what they are doing. Of course it's always suspected that is what they are doing. But it's really old school. You say you don't want to sell, won't sell, not at any price, reject all offers until one comes along that is so high you finally engage in the transaction.

I have actually run into this before many times.

Also part of the tell tale sign is that she plans to rent it out. That is another signal that she just plans to wait. Most likely the lease will be written in a way that allows her to terminate it if she wants with some kind of liquidated damages payment.

Now I have seen people not want to sell 'at any price' genuinely because they do run a business, don't need the money, and most importantly (and this is key) it gives them something to do. Typically they are older people who want to show up for work every day. This woman doesn't fit that MO though.

My bet is it's a selling strategy.