While there might have been a time when this defense would have been believable, particularly for someone who had not previously served in government, Ivanka Trump would have had to literally have slept through the entirety of the presidential campaign to not be aware of how much a similar use of private emails cost Clinton politically.
Trump was there at campaign rallies where her father led “lock her up” chants. She was at the Republican National Convention, where “lock her up” chants took place during virtually every speech. She was at the presidential debates, during at least one of which President Trump stated point-blank that as president he would seek to have Clinton prosecuted for her email practices. There is no way Ivanka Trump was unaware of the seriousness of the issue.
That leaves two possibilities. One, Ivanka Trump is egregiously incompetent and honestly did not comprehend what the entire email scandal was about at its core. Two, she walked into the White House with the air of entitlement and invincibility that could only come with being an untouchable nepotism hire for whom the rules did not apply.