Your GF's refund cannot be seized for the delinquent child support that you owe. You have not provided any information that would help us determine if your GF can claim you as a dependent. If you made more than $5050 in 2024, she cannot claim you as a dependent. If you did not live with GF for the whole year in 2024 she cannot claim you.
To help your GF:
IRS interview to help determine who can be claimed:
https://www.irs.gov/help/ita/who-can-i-claim-as-a-dependent
CREDIT FOR OTHER DEPENDENTS
https://ttlc.intuit.com/questions/4499708-what-is-the-500-credit-for-other-dependents-family-tax-cre...
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**