I am presuming we are talking about children in their teen, to late teen age, as this wouldn't really be a serious concern with a younger child. Children should be allowed to pursue their own career choices; even when they seem unrealistic to the parents. People learn by making choices and learning from mistakes. If a parent keeps their child from making their own choices it can cause harm, two-fold. One in a sense that the child is not able to make their own choices and be independent. Secondly because it can cause a level of resentment towards the parent, "I would have been an artist if my mother only believed in me." You can give your child advice, and try to encourage behaviors you know will lead to positive outcomes, however ultimately it is their life and they have to make their own choices.