How much does my dependent have to make in 2024 to file taxes

If their only income is W2 and under 14,600 they do not have to file a return except to get back any withholding taken out.  If they got a 1099NEC or paid cash they have to file it as self employment no matter how small.

Filing requirements for a dependent
https://ttlc.intuit.com/community/children-dependents/help/do-i-need-to-file-my-own-taxes-if-i-m-a-d...

1. $400 or more self-employment income
2. Over $1,300  of unearned income
3. Over $14,600 of earned income
4. Your gross income was more than the larger of:
   a. $1,300, or
   b. Your earned income (up to $14,150) plus $450.