Those so called advisors will get paid no matter who they are, family or not. So...non issue.
A president is entitled to trusted advisors. No one person, no matter how smart, can get their arms around all of the issues this country faces without them. So...who would you trust more than family members?
It is an issue if they have no skills or experience and thus cannot advise the president on anything.
As to family members -- the question remains, what do they know about the issues that would qualify them to advise the president! As far as I can tell, Trump's children and the son-in-law have lived lives of luxury -- if not all their lives, then certainly in recent years. They are so far removed from the struggles of everyday Americans. About all they think they know comes from the media and we all know how inaccurate and biased that is. Have any of them been to hell holes like North Korea or Africa? What do they know about terrorism? When was the last time they visited a dying former mill town or a slum, or better yet, lived for a time in one of those places? Have they ever tried to stretch a Social Security check to last till the next one comes?
President Kennedy had his brother, Bobby, as Attorney General. But at least Bobby had a law degree and legal experience. What do the adult Trump children and the son-in-law bring to the table?
Trump supporters elected a president. They did not elect a royal family. If you want to live under a monarchy, there are a number of them around the world with plenty of do-nothing relatives the taxpayers have to pay for. The founders did not intend for this country to have a monarchy and I for one would rather live in a country without one.