There was a study released this week showing that people who use tanning beds are up to 4X as likely to develop melanoma:
http://www.dispatch.com/live/content/local_news/stories/2...
I have olive skin from my dad's Italian heritage, and I've been to a tanning bed once in my life - it's not worth the risk.
Interestingly, tanning beds can be good for some people in small doses. My FIL has psoriasis, and 90 seconds/day helps the condition.
BUT, the risks are SO high. At 15 she thinks she's invincible, and I did to until almost 2 years ago when I was diagnosed with cancer 2 days before my 33rd birthday, the day before my son's second birthday, and just before my daughter turned 11 weeks old. Believe me, cancer is a risk, and it's real, and it's awful to go through treatment.
So here are some links that may be helpful in her really understanding the risk despite Dad's ignorance on the issue. I'm including the website for a girl I went to high school with (she would be 35 right now) who died from melanoma, the most dangerous kind of skin cancer.
New people know that your skin is the largest organ in your body. It's really critical to treat it well because of how susceptible it is to so many different things.
http://www.healthychildren.org/English/safety-prevention/...
http://www.mayoclinic.com/health/tanning/HQ01487
http://www.ashleyfistercolefoundation.org/ashley.html