My children, now 5 and 7, have been seeing Dr. Alazard (St. Rose Pediatrics) since the day they were born. He definitely is familiar with each of my children and treats us all (parents and children alike) with a great deal of professionalism and respect. When you call up to book a well-check visit, you do book the appointment with your regular pediatrician (in our case, Dr. Alazard).
If you are calling in for a sick kid visit, you can request to schedule an appointment with your preferred doctor but if he/she is not handling sick-kid visits that day or is completely booked, you may have to schedule the appointment with another doctor in the practice (they will tell you the name of the doctor and ask you if it is okay) or wait a day or two to see your preferred doctor. It's your choice.
I hope this helps.