It's illegal for a reason.

So, she has no official job and no official security clearance but she's attending official meetings and meeting foreign diplomats. And lol you guys are all 'no it's ok, they like her'. Well, no it's not ok.

Maybe a better question is why he's reduced to relying on family for what should be the most sought after positions in the US government. When 6/9 top positions in the state department are vacant and your excuse for diplomacy is to send your daughter, how is that not a problem?