My neice took approximately 2mg of a vicoprofen (hydrocodone and ibuprofen). She is on probation. How long will this stay in her system to be detected on a urine drug test.

Not medical. This site is not for answering such questions. If she took these without prescription, then I recommend that she get help for this problem as priority.
Caution. Be careful about your own enabling behavior, eg, asking this question for your niece. She needs to face consequences for her behavior through a treatment program and comply with probation. Most enablers are well-intended and think they're helping a loved one, when they may be perpetuating a problem by doing too much. Try to step back and let your niece cope. She must pick herself up. Take care.