What does a fever mean?

So my doe Totoro has quite heated ears, I've checked her nose and she has a bit of wetness at the bottom, no snot.. Her teeth look good from what I understand, she is biting her lip just a bit so I gave her a branch and empty toilet paper roll to chew. Her vent is clean, no bloat, her genitals are quite purple for a 3 month old in my opinion but anyway.. She's still eating, drinking, playing. But she appears to be running a temp, I looked down her ears and saw no mites but I'm gonna keep a watch on her and see if she starts shaking her head any.. What could be wrong? Is she actually running a temp or am I being silly?

Buttons, I wish I could help, but the honest truth is that I don't know. I googled normal temperature for rabbits and there is lots of information, but it's hard to sort it out. One site did say that ear temperature is often not a reliable indicator on its own. (I know when my cat races around the house, her ears are very warm when she stops, but they soon go back to normal.)

Here is a link to a House Rabbit site that gives the normal range for rabbit temperature (rectal), respiration and pulse rate. Hope it helps.
http://rabbit.org/temperature-and-respiration-rates/

Rabbits have a high starting temperature already. They will feel quite warm compared to human skin and some other animals. Especially in a warm room or during the summer when their ears act as heat regulation to release body heat. It's usually not a concern without other symptoms and the only way to confirm it would be to test their body temperature.

Well compared to my other rabbits her ears are quite hot and when I gave her willow bark tea she downed it and ate the powder from the bottom

Treating a fever is often not useful. A fever is not a disease. It's a symptom and commonly a symptom of an infection that either won't go away or of something where the rabbit needs isolated and removed from breeding, if kept alive. If you confirmed a fever you would want to try antibiotics if treating and isolate the rabbit in case it was one of the more dangerous contagious respiratory infections. Generally unless there are symptoms of an infection that is not contagious such as a wound or internal organ infection the rabbit is not treated to prevent creating weak rabbits and medication resistant strains of disease. Many internal infections without a wound would result in an expensive treatment up to a chance of needing spayed for a uterine infection, possible ongoing health issues from what caused the infection in the first place, and unlikely to be suitable for breeding. It makes it a bit pointless to throw a fever reducer at an unproven fever except as a cheap way to try to help a pet survive that you don't plan to have around other rabbits in case it carries something contagious.

Even natural sources have their side effect risks and can create strains of illness resistant to them. It's not always a good idea to use them without a reason. Just because it's willow doesn't mean it doesn't have some of the same secondary effects as giving a measured dose of aspirin. Even before modern medicine there were people specifically knowledgeable in the use of natural sources of chemical compounds that would treat illness so they could identify possible risks of using something and the length of time it was safe to use. That is why I am against throwing various herbals at unconfirmed or unknown illnesses. If there was an identified injury causing pain or an abscess without blood flow (you wouldn't want to give a blood thinner if you might have to cut open something with blood flow) then sure it has a proven need with a problem you do actually want to treat and keep the rabbit around with probably no risk to your others. There are a handful of bacterial abscess producing illnesses that are contagious beyond wound to wound transfer and can infect healthy animals but you will probably never see them so usually direct treatment of the single rabbit and continuing to house it near other rabbits and to breed it after recovery is perfectly safe.

Stress or actual physical heat can cause heated ears, so if you bring a rabbit in from outside in winter, expect their ears to warm up. Also, too much handling of a rabbit that is stressed can do it.