possibly.. but why is she doing this anyway.. Its not healthy ( at all ) She should realy stuff. and if you were a true friend you would tell her to quit...
Cocaine usually stays in your system for about 3-5 days depending on how often you use it -- if you use it a few times a week then it can stay in your system for up to 10 days.Could you test positive for cocaine just by touching it?
It depends on what kind of test they do. Hair, blood, urine.
It days in the urine for a few days, the blood a week or so and the hair, well you can tell up to a year with that test.