Is Jivanka still advising Trump?
No, they've commented that they want nothing more to do with Trump's political ambitions. I suspect they want to work their way back into the good graces of the Manhattan social scene that they've been ostracized from.
This being said, in the extremely unlikely event Trump finds himself returning to the White House, I have no doubt they'll move back into the West Wing and fire all the MAGA people like they did the last time.