As for Ivanka Trump, I know almost nothing about her, so I can’t tell you if she is religious, not religious or not-Jewish. I also don’t think it’s fair (or mutar) to talk about specific people on-line. It is not her fault that her father is famous and that does not justify talking about her publicly (or at all!).
I also want to stress again that the issue here is not what someone does or doesn’t do, but whether or not he denies the validity of the Mitzvos and says that they (or any one of them) do not have to be kept.