My 4 year old daughter's liver enzymes are abnormal, and also has gallbladder stones. what could have caused that?

Multiple Causes: Hemolytic disease, hepatobiliary disease, obesity, prolonged parenteral nutrition, abdominal surgery, trauma, ileal resection, crohn's disease, and sepsis all may lead to an increased incidence of gallstones in the pediatric population. The first step would probably be a hematology evaluation.

Hematology eval?: Gallstones in a 4 year-old are uncommon, but when they do occur, it is often not due to cholesterol stone like in adults. They may be pigment stones that result from abnormal breakdown of red blood cells. Hereditary spherocytosis and other disorders can do this and consult by a hematologist may help, as could a pediatric gastroenterologist/hepatologist.