Decades ago there was reason in your point of view. Family members were not part of the political machine or process. Today, however, family members jump right into the fight. Spouses campaign for the candidate. This makes them fair game whenever they promote their favorite. If the children do not participate they should not be included in the smear tactics of the opposition.
But I doubt that you are going to convince the Democrats about this topic. Exempli gratia: the Palin family.
If they didn't expect any comment they would keep the children and pic of family out of the limelight. Very much like Clinton's did for Chelsea.
bumper sticker - honk if you will pay my mortgage
"The problem with Socialism is that eventually you run out of other people's money." attributed to Margaret Thatcher
"A wise and frugal government, which shall leave men free to regulate their own pursuits of industry and improvement, and shall not take from the mouth of labor the bread it has earned - this is the sum of good government." Thomas Jefferson