I would remind the parent that being prepared is the key to effectively taking care of the young children. Let her know what your routine is like and emphasize that children in a good routine are often more relaxed and happy. You have the equipment and the space to deal with multiple children which makes taking care of the children easier on you. I would also tell her about your meal prep eg. do you prepare some foods ahead of time, what are the children doing when you are preparing your meals. Giving the parent a good idea of how you handle various situations with the little ones will help parent realize that you are prepared, organized and most importantly are yourself relaxed and confident in your abilities.