I wouldn't worry about how high the temp is- I go how by the child is acting. If the child isn't drinking I would worry about dehydration. If she's in severe pain (you know your child so you would know the signs of this) I would worry.
I don't generally give tylenol unless the child is really really uncomfortable and can't rest. My ds has been ill since Wednesday evening. Wednesday night he had a fever in the 104's (104.5 when I temped it). I did eventually give him tyelenol that night because he was so uncomfortable and screaming all night long. No rest is not a good thing when you're trying to heal. Last night his fever was back up to high 103's, low 104's. No tylenol last night but he's acting much better this morning (he just found my cell phone and decided to give Grandpa a wake-up call
I generally don't treat fevers because they are there for a reason. It's the body's way of fighting off an infection. I don't mess with that, unless the child is in severe pain and can't rest.