If the snake isn't in the warm spots or near her enclosure, I'd start systematically searching every nook and cranny of the house... and I mean search everything. Drawers, folded clothes, pockets, behind books on the shelf, in the bed, the cupboard - everything. Don't dismiss a hiding place because you think there's no way she'd fit. Snakes are excellent at squeezing themselves through gaps like you wouldn't believe.
The other trick I don't think anyone has mentioned is to wait until the lights have been out for a while, then search the house with a spotlight.
Good luck and let us know how you go.