No offense, her Dad's funeral interrupted every damned broadcast for over a week. It was the funeral that NEVER ENDED simply because they could use it to attack the POTUS. AS far as I'm concerned, the presence of Ivanka and Kushner was sheer class. The McCain family dragging their dead traitor father around for weeks on end was anything but.
By definition, one cannot “crash” a memorial service that is open to the general public without qualification. Done with good grace, attending the memorial service of an adversary or a person one dislikes or has been at odds with is a sign of respect.