maid elena

I agree with the OP ; also couldn't stand her. She was extremely harsh towards Nick, possibly because she felt he had ingratiated himself into the family, not totally the case, as he and Toby were good friends at Uni, and in any case not her business. She was even condescending when Nick first entered the home and smirked when he mistook her for Toby's mother. A thoroughly unpleasant woman.

I applauded her acting but continue to dislike the character.

My late old mother was once a nanny to aristocracy, and can very well recall from her many tales to me and close family in her retirement years, that most certainly not all guests of the family were viewed as interlopers, or suffered behaviour as shown by Elena towards Nick. Manners were observed very closely however, and if the guests knew how to hold a knife and fork! (Pity those who didn't, then my old Mum would have been, as another poster stated, quite snobby about them, discreetly of course). However, in that department, Nick was almost faultless. I say almost - watch carefully when he is first at the dining table with Toby and parents, he was unaware how to eat asparagus, then subtly took a lead from Toby and his father. (My old mother would have noticed that, definitely!) Being young, I felt he simply enjoyed associating with the rich and famous, basking in their shadow. Bear in mind too he had a massive crush on Toby, virtually hero-worshipping the guy, so must have been over the moon to live in the same house, and later, considered one of the family, next best thing to a civil partnership, without the sex!
I agree, for "no good",Elena had many others to use that description of but hardly Nick.
Yes, an excellent point - her disdain when Nick first arrived in the Feddens' drawing room, was indeed palpable, I truly felt for him!