Did Dad pay for over 1/2 of her support?  If so, she is his dependent, and therefore she can't claim any dependents on her tax return.

If Dad did not pay for over 1/2 of her support (and therefore your client is not Dad's dependent), her income is too low to claim the Child Tax Credit.

Is $1500 her gross income?  Or is that after expenses, such as vehicle expenses?  If that is her gross income, the expenses will lower that quite a bit, and EIC will likely be fairly small.