Sparkle, I am so sorry to see this thread! But I'm glad to see she's doing better. Prayers are going out y'all's way.
I wholeheartedly agree with Bug and others who said researching online can just send you in to a panic.
I haven't been through your daughter's situation, but I was sick all the time when I was younger. Colds, flus, ear infections, strep, you name it. In 6th grade, something started to just feel not right with me. Went to the doctor and they thought it was strep again and put me on antibiotics. They didn't take a test for it though, and ultimately they were wrong. The medicine didn't help me, and I was feeling terrible all the time, fever off and on, nauseau all the time, achy everywhere. My mom kept taking me back to the doctor over a period of several months, and they started saying nothing was wrong with me. Obviously THAT wasn't true.
Eventually my mom took matters into her own hands and took me to an ear, nose, and throat specialist. They did a simple swab test in my mouth and something with my nose, and the results took maybe a week to get back. Turned out I had some come kind of nasty bug (they called it a virus, but it could be treated with medicine, so I'm guessing it wasn't technically a virus) that could have eventually turned into meningitis if it hadn't been treated. I got put on the strongest medication I had ever been on for about 2 weeks, and then finally I felt better. As bad off as I was for months, one bottle of super strong antibiotics cleared me right up.
So, even if your daughter's white cell count goes up again, it doesn't necessarily mean it's a disease. Obviously no two stories are the same and I'm not saying something like my old problem might be the case for your daughter, but I thought you might like to read about it anyway. Prayers to you all!