I saw this movie when I was fairly young, in the age when you still rented movies. Also, I'm born in Sweden so even if I would remember the title, it would be in Swedish, which could be completely different. This film has stuck with me, and I really want to know what it's called.
The story starts out with a teenage girl explaining her family situation, it's a lot of divorce and remarrying. Her dad has been married twice, and his current girlfriend is pregnant.
Her mom and her "sister" are like best buds who sits and complement each other on each others looks.
The girl then decides to run away.
Also, her dad's older son falls in love with his current pregnant girlfriend, and they end up together at the end of the movie, while the dad goes back to his wife no. 2.
I also very vividly remember this photo at the back of the cover where the mom and the "sister" wear matching clothes and are putting their sunglasses on.