Your little friend is commonly called a cross orb weaver or European garden spider.
They are one of my favorite spiders, I welcome them. As a kid, I even played with them.
No, you don't need an exterminator for these, and they will die off with the first frost anyway.
Just let her stay the rest of the season, and no, they don't normally come indoors, they need their nightly web to eat.
http://bugguide.net/node/view/848401/bgi...
One of my little friends:
I live in mid michigan area. Trying to make sure i dont need a exterminator. Just killed one last night now this one is outside the bathroom window.. i zoomed in, its about the size of a 50 cent piece give or take.
