Claiming

Was your GF's only income for the whole year just $800?   She does have to file since it was over $400 of self-employment income, but she will only get a few dollars   (less than $300) of EIC if she claims your child.  Assuming you made more than $800, you should file as Head of Household and claim the child.  You should be able to get the child tax credit, and perhaps earned income tax credit, depending on how much you earned.

GF does not enter anything about the child on her tax return at all.    If your GF lived with you all year, you can also claim her as a qualified relative dependent for the $500 credit for other dependents.  GF will need to say on her own return that she can be claimed as a dependent.

The child cannot be claimed on two tax returns.

WHO CAN I CLAIM AS A DEPENDENT?

You can claim a child, relative, friend, or fiancé (etc.) as a dependent on your 2024 tax return as long as they meet the following requirements:

Qualifying child

• They're related to you.
• They aren't claimed as a dependent by someone else.
• They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
• They aren’t filing a joint return with their spouse.
• They're under the age of 19 (or 24 for full-time students).
• No age limit for permanently and totally disabled children.
• They lived with you for more than half the year (exceptions apply).
• They didn't provide more than half of their own support for the year.

Qualifying relative

• They don't have to be related to you (despite the name).
• They aren't claimed as a dependent by someone else.
• They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
• They aren’t filing a joint return with their spouse.
• They lived with you the entire year (exceptions apply).
• They made less than $5050 in 2024.   (Not counting Social Security)
• You provided more than half of their financial support.

When you add someone as a dependent, we'll ask a series of questions to make sure you can claim them. There may be other tax benefits you can get when you claim a dependent.

Related Information:

• What does "financially support another person" mean?