My daughter is moving in with me this year. I get child support taken from my paycheck weekly. Can we create an agreement (signed by both of us & notarized) stating that she will give me half of the weekly support (since I will now be keeping my daughter & she'll be living with me?) If so, what if my ex starts keeping it? How will that agreement we created between us, hold up in court?What would be the quickest most efficient way to get the modification done? How long would it take? Would we need to get new financial affidavits?