I guess she doesn't want it siting empty and her receiving no income? Bummer for you guys though. You never know, the seller might get a buyer who wants vacant possession asap and you get to leave early. That's what happened to us when we sold on of our houses. We paid our tenants out in cash + removal expenses just to get the house sold.
I really don't want any opens conducted while we're still living here though. I guess what we want is for the landlord to allow us to move out before it's on the market and opens are conducted.