I agree with jassy, there is a difference between not being cat friendly and being a kitty killer. We had the shelter cat test Violet and she passed fine. Once we got her home, she ignored Phoebe for the first few weeks. Then she decided kitty was interesting and started barking at and chasing Phoebe. Phoebe growls and hisses at her and pops her with her paw and Violet just barks. So had she done that at the shelter, they may have labeled her as not being cat friendly, but she really just wants to play. As time has passed, they are becoming friendly with each other and Vi rarely barks at or chases her and Phoebe doesn't growl and hiss.
Now there is a lab mix next door that goes beyond and is a cat killer. Matter of fact, she killed my last cat and it took me 3 years to finally get another cat, my Phoebe. No cat is safe around that dog as she tore through a screen to get at my Jasper.
I'd ask the shelter what type of behavior she exhibits around cats. If it's just chasing and barking, I wouldn't be too concerned, but if it's aggressive and threatening, I would have to pass on the pup. Let us know what happens.