welcome to HealthcareMagic
of your sister is high at 5.8 and the urea levels are also high but since she is young and her general condition is fine and her other reports are fine then the doctors will first advise her to under go dialysis
to reduce the creatinine and if she responds well to the treatment then may be transplant surgery
can be avoided.But if the response is not there then she may require transplant.Let her reports come and let the Nephrologist
see the reports then he will be the best person to decide the line of treatment.As far as possible i feel he will give your sister a chance to undergo dialysis which is a option before thinking of transplant.