How do you address a serious hygiene issue of an adolescent neighbor if you're concerned she will have negative social and health ramifications if she doesn't receive help?

This problem should be up to her parents. However, if her family is disfunctional and if you have sort of "adopted" this person (they are over at your home often) you could start by getting her interested in how to dress. It's easier with a girl because you can get around to the negative hygiene problems by starting out on how to put on make-up (less is best.) Use yourself as an example, and while you are teaching her how to dress or put on make-up slip in that you know hygiene is very important and you shower at least once a day, etc. If this person respects you and looks up to you then they are more apt to copy cat you. It is very kind of you to take a vested interest in this young person and you are absolutely right in trying to teach her about hygiene. Perfume doesn't cover-up body odor. You are in a very touchy situation if she has parents. I would probably have this young girl over, have some fun with make-up (every so light on the make-up) and even buy her some. A little light lip gloss, etc. Perhaps you could find some second-hand clothing at a store or even buy her a couple of blouses, etc., to get her interested and to realize there are nice things out there when she is older and working. I would then talk more about myself and say, "I can't stand my hair dirty so I wash it every day and no more than two days later. I also shower every morning and love the smell of the shower gel I use." This will peek her interest so it's a good investment if you get her some body gel and hair shampoo and she'll be more enclined to want to take showers. You're one great person to take this attitude and try to help this young girl instead of judging her! I'm pleased to meet you! Good luck Marcy