Of course the paralegal states that you need to sign a new agreement.  They want more money from you to change the agreement.  Tell them okay then you will stay with what you have and thanks for the advice.  Then when you get to court next month advise the court that there has been a change in the income of your spouse and that a modification of the agreement needs to be placed on the record (i.e., under oath and with out the need for a new paper to be signed) and could the court so order the modification of the one paragraph on consent of both parties and with out the need to draw up new papers.  The agreement between you on child support is always subject to scrutiny by the courts as the best interest of the child are tantamount here.  See what the judge says.  If the judge says that you need a new agreement then ask if you can add an addendum rather than an entire agreement and draw it up yourself.  Again, the court will review it. Good luck.