How long will it take to clean body system from weed? she needs to pass her medical check up.

You can't 'clean': Weed out of your system. Single use marijuana may be found in blood for 12 to 24 hours. Regular use marijuana may be found in blood for 2 to 7 days. Single use marijuana might be detected in urine for 1 to 7 days (or more) and regular marijuana can be detected in urine for 7 to 100 days (longer periods have been reported though).