please get her cyclosporin blood level tested to see if it is abnormally low or high, both of which can cause the creatinine
also get a urine culture to see if there is serious urinary infection which may need further antibiotics.
if both situations are not there then she may require a biopsy
of transplant kidney
by your nephrologist
to drcide about further action and some change in immumosupressive medicines.