well i have 3 14 year olds and boy will they refuse not to go to school.you should talk to them calm them down and ask the principial if there is anything going bad in her school.if not let her relax with you for a day and then take her to the doctor just in case ok goodbye

Sounds like the teen is in a tough situation.  Adolescence is stressful as it is when teens try to figure out who they are and where they are headed.  When living in a shelter is added into the equation, the stress level goes up exponentially due to being displaced, having atypical family situation, or experiencing  various life misfortunes.  All that can contribute to feeling different than peers, or even ashamed and depressed.

The teen in question might have emotional disturbances related to her life experiences.  The first step would be to provide her with counseling and evaluation by a mental health professional.

Please read this article about childhood depression:
http://www.pluggedinparents.com/index.php?option=com_content&task=view&id=450&Itemid=0

The teacher needs to work with the  parent or guardian to set up a daily reinforcement and monthly reinforcement system. This will require daily notes home wherein the teacher will determine if the behavior deserves a plus and will mark a plus on the calendar for that day. For a weekend special, the student will require 4 out of 5 daily plusses. A weekend special is an activity with a friend out of the home, and otherwise inhome activities. For 5 plusses every day for the week, the student gets an activity out of the  home, AND has the entire weekend to go out and have activities with his/her friends.

If the student goes to school 3 days, the student will have an indoor weekend but has availability to movies and video game players. If the student goes to school two or only 1 day, the student will have an indoor weekend without movies of game players. If the student manages to have a weekend special every week in the month, the student will be awarded with a second weekend special.

What is a weekend special? This is largely determined by what you think is appealing to your child and is affordable over the long term, such a a video rental, a movie rental, a trip to the mall, a $5/10 spending money,  a trip to McDonalds (with a friend), going to the movies (with a friend), a $5/10 gift card to their favorite store, perhaps admission to a museum (with a  friend). You know your child, so you know what he/she would make it worthwhile for them to go to school.

It is equally as good for the parent to keep a calendar of plusses (no minusses, that's punitive and unnecessary, and will be discouraging) at home as the teacher  keeps a calender at school as visual reminders of success, and the teacher may choose to have a daily reinforcement, such as a piece of candy or a trip to the grade home office after they check in at home room for a congrats and to keep it up.

I'm sure there are other ideas, but this is a positive method which focuses on success and ignores failure as the lack of a plus is evidence enough, and no  harping on the how many plusses the child didn't get, but emphasizing and rewarding the number of plusses the child does get. It makes the whole attendance issue a challenge to reach toward the best the child can achieve, and when the concept is explained to the child, it has to be explained in a positive way (i.e. if you achieve 2 plusses you earn..., if you achieve 4 plusses you earn...). Keeping it all positive makes it a positive challenge that your child will see as an easy way to get something worthwhile.

I hope this helps.