Thanks for your query,based on the facts that you have posted it appears that your 2 years old daughter leaks few drops of urine in her dipper.
This could be most likely due to Pneumococcal infection of bladder and urethra
which is common in children.
Please get her routine urine test and urine culture done to confirm the diagnosis and take appropriate antibiotic as per advice of your Paediatrician.
Clean her genitals and urethra with warm water twice daily.
Thanks and Regards.