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"She heaved a sigh of relief" is the idiomatic expression.
It's certainly colloquial English to say "down the hall," as if all halls were ramps, instead of "through the hall" or "along the hall." "Down the aisle" is another popular colloquialism; however, my son the architect says the saying was literally true in some old world cathedrals where the aisle actually dropped from the narthex to the nave. Even in newer churches, the illusion of "down the aisle" is present with vaults over the aisles quite a bit higher than the church entrances.