
Originally Posted by
OliveOil_Med
Yes, but her older sister is in Slytherin, and JK has mentioned in interviews that the Greengrass' are yet another old pureblood family. Keeping that in mind, Slytherin does seem like the most likely choice. And even after all that has happened with the war, I don't see Draco having changed so much that he marries the Greengrass-female semi-version of Sirius Black.
But, if you are to place Astoria in a House other than Slytherin, my advice would be to have it well planned out so that it seems believable. Because children from Slytherin families being placed in Houses other than Slytherin has become something of a cliche these days.