I'm glad you took her in. The fluids are very likely a major part of her improved comfort. Dehydration can have huge effects on the body, especially in little animals.
The diet you are describing sounds reasonable - any chance of any change in the ingredients that might have made her sick? Most SGs really like insects, eggs, and other protein sources - it's unlikely that the protein alone would cause a problem, unless she eats that to the exclusion of other foods.
Hyperglycemia isn't likely unless the vet included some sugar in the fluids he gave her.
If she was developing a systemic infection (sepsis), the antibiotic injection could also be a factor in her improvement.
Companionship is very important to SGs, and a lack could be a source for depression or decreased survival drive. Companionship provides warmth, interaction, environmental enhancement (play), and some competition, which sometimes helps improve eating.
Before pursuing any new SGs, try to get to the bottom of her illness with the more knowledgeable vet - hopefully he or she will be able to help diagnose her problem.
Keep her warm, keep providing fluids, easy to eat foods and foods that she likes until her appointment on Monday.
I hope she continues to feel better - good luck!