You responded to my similar question a few days ago. I hope that things are going better for you.
Our 2 1/2 year old has been doing the same thing. After about a month of staying alone in his toddler bed and sleeping well, he stopped sleeping almost entirely and seemed really anxious if we left him at night. We think it might have been related to a thunderstorm.
We unsuccessfully tried just returning him to bed over and over (and over and over), but it progressed to a game and then he became hysterical and exhausted as the hours wore on. We also didn't talk to him during the process, which was too difficult on all of us.
I ended up buying and rapidly reading the book "Solve Your Child's Sleep Problems" by Richard Ferber. He has a lot of strategies that we are more comfortable with, and he does a very good job of explaining sleep science and stressing that helping a child fall asleep, even if he cries for you for some time, is the right thing to do.
The action plan was to put a gate at his room and let him cry for short, but increasingly longer, intervals. Then go to him and reassure him and leave (last night, the max we left him was 10 minutes). So, we tried it last night and he fell asleep, in his bed, after only an hour and a half, and when he woke twice at night, he cried momentarily - hardly even long enough for me to get out of bed and check on him - and fell back to sleep on his own. It is only one night, but I'm more encouraged than I've been in more than a week. An hour and a half might seem long, but previous nights we spent more time putting him back in bed (and thus he spent crying) than he would spend sleeping.
Of course, if your daughter is sick and this explains the wakefulness then you might not even need to try something else.
As for naptimes, I put a soft blanket down on his floor for one nap and laid with him until he fell asleep -- no patting or rubbing his back - and he now will stay in the room on the blanket on the floor for naptimes. That is definitely helping because he isn't too overtired to relax at bedtime. Like I said, it has only been one day but things appear to be improving.