If mom doesn't go back to work till June 11 I would say it is too soon to consider integration because it has to happen over and over for it to become familiar to the child and the parents - integration is for the parent not the child - it is so mom can gradually wean herself off her dependency on the child and realize she has to go to work, etc.

The week before care is to start child does integration and comes at what would be the mom's normal drop off time as in they are practicing and adjusting the morning routine at the same time. Mon child stays for an hour, Tues child stays two hours or till morning nap but goes home to nap, Wed child stays morning and has snack and nap but goes home before lunch, Thurs child stays till just after lunch, Fri child stays the full day.