Yes if your girlfriend does not have to file a return because she earned less than 3900.00 in earned income and she is the sole physical custody parent of the children and their father does not have a court order saying he can claim them, provided she and the children lived with you the entire 12 months of the year and you provided 50% or more of the support for them you can absolutely claim them!! All of them even the girlfriend and it wont hurt her food stamps so long as she informed them you live in the house, if your not married in California anyway they dont count your income provided she buys and prepares food for her and the kids separate, now if she didnt tell them you were in the house then she could be in big trouble. She can report you living in the home and not lose her food stamps as long as she buys and prepares food for her and the children separate. You can still claim all 3 of them though and nothing legally will affect you or your tax situation.
