The text might be a bit above my Japanese skill...I'm around N4 level.
But anyway, this chapter has been fan-translated, so I did have something to check it against. The translator translates the final sentence as: "I’m just a nice maid girl who can only smile politely while receiving such abuse."
But I'm not sure how this connects with the original Japanese. Although, I'm pretty sure what I'm failing to understand has something to do with the use of いいこと.
The best I've been able to come up with in understanding the spirit of the original Japanese is: "As much as it would serve her right, I'm just a maid, so I can't raise my hand against her."
I'm still confused as to how the first clause relates to the second clause through the を particle, though.