I totally agree with not letting her go to guides on a day when she has missed school. And certainly not letting her be rude.
Still, I would like to point out that it is possible to have an earache even without redness in the ear:
if your Eustachian tubes are narrow, it can make you very uncomfortable whenever you have a cold, because of bulging eardrums; this pain can come and go, so may not be apparent when GP is looking
if you have had a lot of pain, your nerve system may go into overdrive so you feel the pain even after the cause is gone (like feeling an amputated arm). When my dd was in hospital she shared a room with a girl who had developed chronic earaches after a bad bout of salmonella.
it can be quite difficult to tell the differences between cold related sore ears/sore throats/achy teeth
Also, children who have a pain and are not believed can get very ratty and rude. And she has been ill.
My dd has had a chronic earache for the last 3 weeks- she goes into school on fairly strong painkillers. GP says it's bulging eardrums, but she also has a chronic pain syndrome. What I have learnt to do, after 4 years of her being in pretty continuous chronic pain, is never to question what she is feeling. Pain is by nature subjective. If she says she is in pain, then she is in pain as far as I am concerned. On the other hand, she has had to learn to accept that it is my responsibility to decide when she is well enough to attend school, pain or no pain. (Not that she always does accept it, but the main point is I accept it.)
So I would sit your dd down calmly and talk the situation through. Explain that she may have earaches that are not actually an illness, that earaches, like a cough, can linger a long time after the actual infection. Try to think of ways of making her more comfortable (early nights, hot drink before bedtime, relaxation exercises, painkillers), but make it quite clear that school has to come before any other activity, and that you will decide when she is fit enough to go to school.
No point in being angry with a child because she is not mature enough to decide which pains are staying-at-home pains, just make the decision for her. Calmly, matter-of-factly, non-judgmentally.