I can't understand the meaning of the bold part. Please help.
The earl was obviously happy with the job she was doing, and he had decided not to summon the housekeeper from London, which she took as a great compliment; but, she thought apprehensively, there was yet time for that tiny slip, that fatal error, which would spoil everything: the dirty dinner plate, the overflowing sewer, the dead mouse in the bathtub. And the the earl would be angry.
She was appointed as housekeeper in place of regular housekeeper due to the fact that the regular housekeeper was ill. But the earl was happy with the work she was doing.
I really can't understand the two thing here -
What is the meaning of the bold part? Does that mean "In spite of all these appreciation, there might be time when error might happen"?
What is the meaning of "earl"? I have checked the dictionary, and I couldn't understand the hierarchy. Can anyone please explain it?