Should a dr wait 3 weeks to see a 5 yr, old who's urine results showed elevated creatinine 3.3 ? or should she be seen sooner and sent to a specialist

Creatinine: A serum creatinine of 3.3 would indeed be an urgent matter in a child however you stated urine level of 3.3. There is much variability in random urine creatinine levels. The only urine measurement of creatinine of any significance is in a urine specimen collected over a 24 hour period. I assume you are not referring to a 24 hour specimen.