psychodad, theoretically, her failure to pay the GAL will have no bearing on the GAL's recommendation. Still, the GAL is a human being and it could work in your favor. It sure can't hurt.
So even the GAL doesn't have her physical address? Something is odd about this. If the GAL is not getting cooperation, that could have more adverse effect than not getting money.
Have you told the GAL that you want primary custody of the child? Or do you not want custody?