A certain lady says that when she was a young girl: I would wear long scarf skirts, big hoop earrings, and bracelets up and down both arms, clear to the elbow. I also wore bandanas around my head and huge amulet necklaces. Maybe I had to get this out of my system before I became a professional, but I'm still prone to bracelets and swooping skirts.

--- Does the bolded part mean something like: I had to change my behavior (get rid of these habits from my system) when I became an adult person (is it what she means by "professional")?
There's plenty of context there.

Take a look at this definition for the idiom: http://idioms.thefreedictionary.com/get+it+out+of+system
There is lack of context. Currently it is obvious that she became pro in some kind of area and such fancy things don't correspond with it.
Students: Are you brave enough to let our tutors analyse your pronunciation?
 BarbaraPA's reply was promoted to an answer.
Great. Thanks. Emotion: wink