The novel not only has gotten that far, it's already over, so i can tell you that the maid doesn't get a happy ending, neither does Mielle or really almost anyone associated with her or remotely an ally of hers.
Aria does absolutely wreck her and she will regret ever trying to destroy her, much like the maid.
Don't read further if you want to wait for the end to see their fates...okay, so they die, Mielle in particular gets her reputation ruined and dies in pretty much the same way that Aria did at the start, Aria even goes for her goody two shoes act and asks to speak to her before she dies in public and whispers to her how she was behind everything, even tells her about her powers, before going away crying as everyone pities Aria for having had such an awful sister as Mielle as she can't say anything, her allies also either die or get their reputations ruined.
Mielle REALLY should have kept her mouth shut when Aria was going to die at the start, i think it's confirmed this isn't an alternate universe or anything, Aria really did go back in time, and it really seems like Aria's power only awakened due to pure stress, fear and anger at her situation and Mielle after she told her she was behind everything, had she kept her mouth shut, she would have gotten away with everything, instead, she gave Aria the means to be given exactly what she did to Aria first, i recall that Aria even whispers to her that Mielle did manage to kill her in the first timeline as Mielle's execution is approaching.
I am pretty sure Mielle died wishing she could go back to the first timeline and punch that Mielle in the face really hard.