First of all, allow me to tell you what a wonderful thing you are doing for your niece.

Logan, in her infinite wisdom as Mother of Many has really said it all. Bounderies are critical - and then stick to it! She needs consistancy. 15 - how many of us can recall all that was going on in our heads when we were 15?

Mutual respect comes to mind - and that will take some time and adjustment. Will you be giving her some things to do around the house that are her responsibility?

And last, but not least - LOVE!

Try to keep a sense of humor reserved for yourself!

My hat is off to you - what a super Aunt you must be!