always thought Kushner was the one most likely to go under the bus. He was at the Russian meeting(s) as well so if anything comes of that I'm sure he'll take the fall though that would almost certainly kill any hopes Ivanka has of running for POTUS.
Haven’t really seen anything to suggest Ivanka is interested in running in her dad’s footsteps. She was barely on the campaign trail and has always been much more interested in moving with the New York/DC power circles than hitting the road. Of course, she’s persona non grata with those people now, and probably too liberal for most of the Republican base anyway. I’m sure she’ll find someone who will pay through the nose for speeches etc.
Don Jr is the most likely one to run for office, but with it being both easier and more lucrative to stick to the Fox News/alt-right news circuit instead, I doubt he’ll amount to much either. As much as people like the idea of political dynasties, Donald Trump was always something of a one-off.