Not going to replay the hillary scenario but just as a reminder, her situation was vastly different.
She set up a server to do the core of her state department business offline, outside the reach of government oversight. It was a deliberate, successful attempt on her part to run a separate operation.
By way of analogy, a state intel agency or military command person is properly disciplined, sanctioned, fired whatever for using private email either because they are an idiot or not following rules etc. However, if you tell me someone working for an intel agency has deliberately, and planfully set a private server to receive and transmit the core of the agency business offline, then that is another matter altogether.
In addition, other crimes were committed along the way that do not, as far as I know, apply to Ivanka. Hillary was issued a valid, legal order by House counsel to preserve all contents of the serve, and within days she blew it away and bleach-bitted it. DO NOT TRY THAT TRICK AT HOME UNLESS YOUR LAST NAME IS CLINTON. Mueller would have someone in prison for doing that if it was done to him during his investigation.
DONE. as in done, done.