Don't listen to the 16 year old.
What's happening to her is completely normal. I've known heavy smokers who started coughing up blood only after they quit... but, the whole hacking process shouldn't last a long time. Go to the doctor if this goes on for over a week... he might at least give her something to help out with the cleansing process.
...but it's pretty damn normal if she's been a heavy smoker for 5 years.
I smoke, but I just cut down to half a pack a day, and it works for me.