chilul shabbos

Question

i work for a mortgage company and today someone called me they need to close by tuesday so i told him no problem. obviously this is a rush job, but i have a very close contact at the bank the head underwriter who does me a favor. i said to her how will you have time to do it so fast she said well ill do it on saturday i just found out she is a jew what should i do there is ample time from now till tuesday she could technacaly do it tommrow