We are missing important information. Which December are you referring to? December of 2022 or 2023? If GF moved in with you in December 2023, you cannot claim her or her child as a dependent.
If they lived with you for ALL of 2023, and GF had less than $4700 of income then maybe you can claim them as dependents and get the $500 credit for other dependents for claiming them. That is all. You cannot get Head of Household filing status, earned income credit, child tax credit or childcare credit for claiming your GF or her child.
If your GF refuses to provide SSN numbers then you have deeper issues than we can help with in a tax forum.
IRS interview to help determine who can be claimed:
https://www.irs.gov/help/ita/who-can-i-claim-as-a-dependent
https://ttlc.intuit.com/questions/3113432-who-can-i-claim-as-my-dependent
https://ttlc.intuit.com/questions/4505693-why-can-t-i-claim-the-credit-for-other-dependents-family-t...
**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.**
