Hello and well done for offering homes to those three hamsters. That's a very kind hearted thing to do
I don't know much about hairless hamsters, but I believe I remember reading that they are particularly prone to health problems and usually die younger than their furry counterparts. I don't know if this is true, but it's sonething to bear in mind.
If she is wheezing it is likely that she has some sort of respiratory infection. If you can see discharge from her nose and eyes, then she may even have pneumonia. Ideally, you want to get her to a vet ASAP. Is there any way you could borrow money from friends or family? Please understand that I am not trying to pressurise you. What you are doing is highly commendable, and if you have to wait then you have to wait .
You are correct that for a respiratory infection is usually a course of Baytril. However, I really would not recommend giving any Baytril until she has been seen by a vet. It could be that she needs a completely different medication, or none at all, and you do not want to be medicating unnecessarily. It could do more harm than good. A vet will also be able to prescribe the correct dose.
As for the eyes, if there is no discharge then I can't think of how to open them. Perhaps there is some discharge which us not visible slightly dpsticking them together? You could try using a damp cotton bud.
She could be drinking at night when you aren't around, but if you are concerned that she is not, then one option would be to offer a water bowl.
It's great that she ate the apple sauce. The fact she is eating is a positive sign. Other good foods for sick hamsters include baby foods (I believe there is a list of safe ones on here somewhere), wet cat food (I use applaws) and porridge. I have never heard about yoghurt being good, but if you do offer it make sure it's not a sugary one.
Keeping her warm and comfortable is the main thing that you can do for now and it sounds as though you are doing very well at that.
One thing you might want to consider is weighing her daily on a pair of kitchen scales. A sign that they are very sick is rapid weight loss and so weighing every day when they are ill can pick up on this quickly before it is too late as hamsters go downhill fast.
I really hope your little girl gets well soon. Let us know how she does. When she us feeling better, I'd love to see some photos of her as I have never "met" a hairless hamster before. I'd also like to hear more about your other little guys
EDIT: Have you thought about switching her from Kaytee natural onto fitch? Fitch is the softest substrate that I know of, which she will need Bering hairless, and also non dusty which is good if she has a respiratory infection. I am sure Kaytee natural is fine too but I thought I would mention it.
Also, I found this page on hairless hamsters which you might find useful as it describes their care needs:
The Hairless Hamster - Hamster Central WIKI