Picking an age range or sex of children to foster

We have four bio boys and our goal was to adopt a girl or two under our youngest bio's age. He was only 1 1/2 when we started the licensing process so we started with 0-12 months. Now he's 4 so we say 0-3 and it will stay that way no matter how old he gets as I'm not comfortable doing any older. Our agency was not happy about us only taking girls, but I was adamant about it. I still get calls for boys. Thing is, we only have one open bedroom for fosters and my bio boys are already two to a room. So it's two girls or two boys only. Otherwise I'd take a girl/boy sibling set. I've almost said yes to boys a couple times, but we will not adopt a boy (again, not feasible space-wise) and they really want all little ones in a home open to adopting them. We've been licensed two years now and have had five placements of baby girls all under age 1. Unfortunately we have not been able to adopt any, but three is still some hope we might get to with our current.As for race, we have stated no preference and have only gotten Caucasian or Hispanic placements. We do have a lot of AA homes in my county, so I imagine they try there first.