Ok haha ..... I'll be a little less blunt .... There is no reason for this parent to be in your kitchen in the first place ....parent should walk in and take the outdoor wear off the child give them a hug and a kiss and leave ....this is not a social visit .... I have a gate at the entrance to my daycare and parents stay on their side. She has seriously over stepped her boundaries and I would rectify it today and if putting a gate up is not an option then i would be at the door when she arrives from now on blocking the way so she can't get past you. She will get the hint soon cause otherwise this will get worse and soon you will have to deal with it twice a week instead of just once a week and you will begin to dread the days she is in attendance.