Other types of income are not taxed before you receive them. This includes money from mowing neighbours' lawns, childminding or being self employed. If you earn this type of income you only need to pay tax on it if you earn $2,340 or more in a tax year (1 April to 31 March). You work out how much tax you need to pay by doing a tax return after the end of the tax year. If you earn less than $2,340 from this type of income you do not need to pay tax on that income.
以上信息来自ird网站，您可以自己看一下，看看孩子是不是不需要交税的