If you have measles exactly, it does not need any special medication and mere fever drug will be enough. You can take calpol tablet and drink a lot of water and get rest.
Yes take only paracetamol 500 twice or thrice a day lot of liquid like soup juice no alcohol. Yes a person can get measles after German measles. Measles cures in 7 10 days unless some other complications.
Difficult to comment without examining the child but rule out kawasaki disease and get her echo done. Treatment will depend upon result of test. It can be a viral fever with rash.