maybe your GF did something wrong because to get the EIC for a child the child must be a qualifying child and only one person can claim a child as a qualifying child.
To qualify for the Earned Income Credit (EIC), a child must meet the following criteria:
1. The child can be your biological child, adopted child, stepchild, foster child or grandchild. The child also can be your sibling, half-sibling, step-sibling, or any of their children.
2. The child must have a valid Social Security number.
3. The child must meet all 4 tests for a qualifying child.
4. The child cannot be claimed by more than one person as a qualifying child.
https://www.irs.gov/credits-deductions/individuals/earned-income-tax-credit/qualifying-child-rules
why are you listing the two non-dependents?
