nor would John Reed have found it out himself

With Bewick on my knee, I was then happy: happy at least in my way. I feared nothing but interruption, and that came too soon. The breakfast-room door opened.
“Boh! Madam Mope!” cried the voice of John Reed; then he paused: he found the room apparently empty.
“Where the dickens is she!” he continued. “Lizzy! Georgy! (calling to his sisters) Joan is not here: tell mama she is run out into the rain—bad animal!”
“It is well I drew the curtain,” thought I; and I wished fervently he might not discover my hiding-place: nor would John Reed have found it out himself; he was not quick either of vision or conception; but Eliza just put her head in at the door, and said at once: “She is in the window-seat, to be sure, Jack.”

**
What’s the meaning of the hightlighted?