My 12 yo daughter became sick 4 days ago, severe vomiting an abdo pain it has finally been diagnosed as appendicitis. what do we do now?

Go to nearest ER: If she truly has appendicitis, the abscess she may have needs either surgical or radiological treatment to drain the pus. This cannot wait.

Hospital: If you're not in the hospital on IV antibiotics, you should be. At 4 days of symptoms, it is probably ruptured, and if so, antibiotic therapy and bowel rest should work. If not, emergency surgery. Consultation with a pediatric or general surgeon is must. This should happen immediately.