Child support

My wife and I have been separated for a year now. We both share custody of our son. I have him for a week and she has him for a week. We both pay half on his daycare. She pays for his insurance premium. My question is I have used the child support worksheet B calculator. She has three other kids from her first marriage. They all three live with their father. She pays only 300 a month for the kids. Does what she pay to her ex affect how much I will have to pay? she only has them(3) every other weekend. Thanks for all your help.