Their mother deserves more credit than she gets. They did live with her after all.
This.
Good old Central European peasant girls.
Mom did ski her way out of a communist country, after all.
They were raised very much like many children -- the mother raised them when they are small and dependent, but the father's influence starts when they start to get independent. Donald brought each of the three eldest into the business when they were teenagers, and has made them executives in his company for the past ten to fifteen years. That's a lot of learning and influence from their dad. Tiffany was raised by her mother in California, but came to visit often, and her dad was certainly involved in decisions about her education. Like two of her siblings, she chose her father's Alma Mater, University of Pennsylvania, for undergraduate college and is reportedly wanting to go to law school next. So Trump is following the old European way of advising a group of children: "legs under the table" -- one becomes a lawyer, another a businessperson, the third in government, the fourth something else, etc. The more "legs under the table" in terms of skills or access, the sturdier the family remains.