I'm quite concerned that she isn't further along by now. The vet may suggest continuing with the antibiotic for some additional days. And/or he/she may wnat to add anti-fungal to the mix (how is the tongue now?).
Try getting some probiotics into her to restore the good bacteria killed off by the antibiotic (e.g. yogurt and/or the powder from probiotic capsules that you can sprinkle on anything). If it doesn't stress her immeasurably, give 3 drops liquid Polyvisol childrens vitamins (without added iron) daily - dribble gently along her beak line via dropper, so she swallows onher own and doesn't choke. Also try fruits because she'll get some moisture that way - watermelon, cut up berries and grapes, etc. Black oil sunflower seeds, if you aren't already doing that - they tend to love them, they are good and can help build strength.
JJ