Teenagers and tattoos

My daughter got her firs tat when she was 18. It was a compromise. I let her get that instead of getting her lip pierced. For my daughter it is a form of self-expression. She is a wonderful girl who has a job and goes to college. She just likes to push the envelope a bit. All of her tatoos are able to be covered up. I can think of worse things. She has never been in trouble. I figure if this makes her happy then she should do it. I also think if when she gets older and regrets it she can always get them removed.