I know this is an old thread, but I felt the need to reply for those who stumble on this later.
Your child would only need to file a report if they earned over the minimum income amount for the year.
The minimum income amount depends on your filing status and age. In 2023, for example, the minimum for Single filing status if under age 65 is $13,850. If your income is below that threshold, you generally do not need to file a federal tax return.
So To answer your question, unless your kids sold their animals for more than $13,850, or had another income in that year causing them to exceed the $13,850 threshold. Then they do not need to file taxes.
