Kid Roth IRA earned income match

Hello!

I have a kid who has $4,000 earned income (baby sitting, tutoring, etc.) in 2022, and I already put it into her Roth IRA. 

I heard that parents can match that earned income and put extra money in their Roth IRA. Does anyone have a link to the IRS site explaining the details? I wonder how much I can put there. 

 

Thanks!