Since this is coming from the closing company, I'd suspect that they have already submitted it to DVC and told by DVC that they were going to buy it back unless it was this price. I'd certainly confirm that but I bet that's the case. If so and she wants it for the higher price, I'd proceed. As recommended, I'd make sure the seller is paying the upcoming maint fees and closing costs for the higher amount. Otherwise, call their bluff and see if they do in fact buy it back. This is not the first time I know of DVC saying they are going to buy it but giving the parties the opportunity to resubmit at a higher price.
Frankly, I'd think DVC would be crazy to buy 275 points at $55 pp. With MP reducing the prices and all of the costs in the repurchase and then selling it again; just seems sort of penny wise and pound foolish.