Front Air Bag Sensor Control problems of the 2008 Mercury Milan

I am 26 years old and weigh 93 lbs. When I sit in the passenger seat of my 2008 Mercury Milan, the sensors in the seat sometimes tell the car that I am a child and deactivates the passenger airbag. I cannot drive in a car where my airbag may or may not be activated. The Ford dealership said that they cannot adjust the weight because of federal guidelines. Something needs to change. I am not going to sit in the back seat. Either the dealership needs to fix the problem or the weight requirement needs to be adjusted.