One of the most important things a parent must be knowledgable about are the financial aspects of this business. Your child is counting on you to keep good records, monitor trust accounts, follow laws related to income tax requirements, assure accurate social security reporting, and know when to consider financial alternatives such as Incorporation.
Although many people mistakenly think all children working in the industry will earn an incredible amount of money, each penny of their earnings should be respected. There are many child actors who do have substantial earnings, and errors in the planning and reporting can be catastrophic.
Always remember the "business" in show business and give the financial matters the attention they deserve.