For what seems like long stretches, I forget about Ivanka Trump and Jared Kushner; and then, in weeks such as this, when both are in the news – Ivanka for her emails and Kushner for irritating the Mexicans by being honoured by their president – I am reminded of what a weird pair they are. The sickly boy king of American politics and Trump’s increasingly diminished daughter.

It was Ivanka who featured more prominently this week, after giving an interview to ABC News. The 37-year-old has always benefited from comparison to her father, alongside whom she seems extravagantly sane and articulate. But even by those low standards, she is looking awfully unhappy these days. As the president’s one unfireable adviser, she was hoarse in the interview and for once appeared close to what she actually is: a slight figure with some business acumen who has been elevated to lunatic levels of national importance. The question I have in relation to Ivanka (and it’s not the most pressing, I know) is to what extent she is deserving of sympathy.

On the basis of the interview, the answer should be none. While Kushner – an impassive, wax doll of a man – appears to be little more than the dim-witted scion of a crooked father, it has always been assumed that Ivanka has slightly more mettle. In the interview this week, she was sufficiently weaselly to be said to have grown as a politician. At mention of the rough treatment of migrants at the Mexican border, she did a long, slow blink – as if such things were an act of weather and nothing to do with her father’s administration – then smartly pivoted, to blame the migrants themselves. (“Seeing children put at risk, running towards the border,” she said, putting the onus of responsibility firmly on the unarmed victims and not on the superpower greeting them with a militarised response.) “It makes me angry that we haven’t been able to come together as a nation and change our laws.”

That is not what makes most people angry about this episode, but Ivanka was already on to the next thing, denying that her father had said the previous week that he hadn’t ruled out the use of lethal force. This was a blatant lie; and, while it shouldn’t surprise, there is a lingering expectation with Ivanka that she will provide a half‑decent word in Trump’s ear. I don’t know where this comes from, other than a basic assumption that women are more civilised than men about, for example, the teargassing of children, and because she is so smooth and plausible. How can she not be mortified by her terrible father?

How can Ivanka Trump not be mortified by her terrible father?

But why should she be? She was raised by a narcissist and a man apparently incapable of empathy, and we know that the narcissistic parent withholds affection until the child does what he wants. There is a good chance that lying when cornered is baked into her psychology, and is as normal a response as she knows.

No, she said sharply, she wasn’t remotely anxious about the Mueller inquiry; and no, there was no parity between her use of a private email for government business and Hillary Clinton’s private email server. Ivanka’s life must be miserable at the moment and there was a mean satisfaction in watching it play out. You could almost see it in her face: the desire to be arbitrating over the fake high stakes of Celebrity Apprentice, in which the biggest decision was whether to send Gary Busey or Denis Rodman home.

• Emma Brockes is a Guardian columnist