Based on the description it seems more like to be some short of intestinal obstruction
since their was "NO FEVER" and was fine but she still has some cough so it might be slight chances of some mild viral gastritis
Now here is what I think
1) viral infection (less likely based on the description)
2) Food poisoning
(in such case all the person who ate same food should have similar symptoms)
(More likely due to green vomit and history of malrotation in other child )
Now let me throw some light on "INTERSSUSCEPTION" it means the tube in tube like one end in intestine goes in and under the other end on intestine like the tubing as we make a joint in the water-pipe/hose.
The mostly it occurs in children under 5 yrs but its not restricted to children adult may have it too
here are some sign and symptoms of "INTERSSUSCEPTION"
1)Severe abdominal pain
that may be continuous or may come and go.
2)Decrease in activity (lethargy).
3)Passing stools that contain blood or mucus.
. Sometimes vomit appears as a green fluid.
CONSULT-Gastroenterologist / go for emergency (if too much abdominal pain/ increase vomiting) As soon as possible,