That was a heroism beyond her.

And she was afraid to speak to anyone lest she should break down.

She adopted a cowardly course.
Afterwards she must explain it to Mrs.Rooke somehow.

She put the consideration of how out of sight: it could wait till the turmoil of her thoughts was over.
She stole from the room, let herself out quietly, and was grateful for the dark and the cool, frosty air.

About five minutes after she had gone Mrs.Rooke came in laden with small parcels.
"The Captain and Miss Drummond are in the drawing-room, ma'am," said the maid.
"Then you can bring tea." Mrs.Rooke opened the drawing-room door leisurely, turning the handle once or twice before she did so.