there is context to that.
her invisible force energy originates from hyperspace, the same hyperspace which is celestial's home:
http://i.imgur.com/48a0I2o.jpg
and she merely removed him out of this plane of existence. Uatu also says that the celestials will manifest another exitar:
http://i.imgur.com/wCS47Hn.jpg
http://i.imgur.com/4Xm6EVC.jpg
so basically she exploited their weakness.
though in fantastic four annual issue 26 kubik says that the celestial's home is outside the multiverse in the realm of the beyonders: