Transiting from DL to Pumping for IFC

Hi parents, my baby is 7 weeks old now, and will be entering ifc soon. Currently, I dl on demand and have no idea how much she takes in every feed. Sometimes she can feed every 1.5 hrs, sometimes 3hrs. How should I establish a feeding routine with ebm instead of on demand so that the teachers can follow when she enters ifc? TIA!