Does Mueller already know everything that Ivanka knows so that he doesn't need to interview her, or is Mueller saving his questions for her until near the end of his investigation, or is Mueller focused on criminal charges against Jared so he cannot question his wife?
Title: "The real reason Mueller hasn’t called Ivanka Trump"
https://www.politico.com/story/2018/05/01/ivanka-trump-mueller-russia-probe-563169Extract: "The special counsel seems to be leaving the president's children for last.
She was in Bedminster, N.J., with President Donald Trump the rainy June 2017 weekend when he decided to fire FBI director James Comey.
She was a passenger on the plane flying home from the G-20 conference in Germany the next month, strategizing about how to manage the fallout of her brother Don Jr.’s 2016 meeting with a Russian lawyer peddling “dirt” about Hillary Clinton.
Ivanka Trump, the president’s daughter and West Wing adviser, also spoke briefly at Trump Tower with a Russian lawyer and a lobbyist who was present for that meeting during the campaign.
Yet the family member closest to the president – and the woman who as a key campaign figure helped lobby her father to hire Paul Manafort, a man who is now under indictment on money laundering and fraud charges, as campaign manager – has yet to be called in for questioning by special counsel Robert Mueller, according to multiple people familiar with the investigation.
So far, only Ivanka Trump’s Washington enemies are actively floating the idea that she might be a “target” of Mueller’s investigation – and therefore not called in as a witness.
…
Like Mueller, Republicans who control the Hill committees investigating Russian meddling in the 2016 election have declined to call Ivanka Trump for an interview. Democratic lawmakers on Capitol Hill, however, do not buy the argument that Ivanka Trump would be of no interest to them or Mueller.
Rep. Adam Schiff, the top Democrat on the House Intelligence Committee, has said that “it would be valuable to have her come and testify.”
Speaking to reporters in January, Schiff added: “if there’s credible information that Ivanka Trump had contact with any of the participants in that meeting at the time of that meeting, she should be brought in.”"