Child acting and self-employment tax 1099-NEC

Both of my children earned nonemployee compensation last year for acting. One was $1700 (minor age) and another was $550 (no longer a minor). The $1700 one got a 1099-NEC from his agency. The $550 one did not. Should both file taxes with this amount as hobby income or as self-employment? The $1700 one also got a W-2 for around $500 for residuals on a prior acting job. Each had total 2023 income less than $3000.