That sounds like your friend was obligated to pay based upon their agreement.. which was made an order of the court. So yes.. your sitch is different. You are under no obligation to pay anything to her until there is an order in place.. your prior payments are gifts .. because you were under no legal obligation to pay... but since you were not obligated to pay.. you do not owe any arrearage.
I know we talked about this before..Please get an appt with local counsel and thoroughly go through the financials with him or her.. it appears the time is ripe for that to happen now.