Read it through once

“The servants sleep so far off, you know, Miss, they would not be likely to hear. Mrs. Fairfax’s room and yours are the nearest to master’s; but Mrs. Fairfax said she heard nothing: when people get elderly, they often sleep heavy.” She paused, and then added, with a sort of assumed indifference, but still in a marked and significant tone—“But you are young, Miss; and I should say a light sleeper: perhaps you may have heard a noise?”