Just wanted to say Jason is completely correct. I know this, because I've been there and done that! I was stupid enough to give someone 30% in exchange for using their kitchen and equipment. You can't make a business that way! They got all my profits and I got nothing but headaches from them.
It's way cheaper and smarter to pay them a flat fee.....not a percentage! You can never get out from under the percentage, the more you make the more they make and they aren't doing any real work. You'll come to hate them when you're paying them more then your putting in your pocket. It's far more fair to pay them x for each referral. She'll make more money off of you then she does from her own business.