If she's referring to the asteroid WF9 then her maths is out, it's due on the 25th of February. I am pretty sure it will burn up on entry. I don't think it's a planet, amateur astronomers would be able to see it if that were true. It's not hiding behind the sun, I have read up about it and think that while it's possible that there may be a planet on a longer elliptical orbit I highly doubt that it will hit the earth and again if it were near we would have spotted it by now.