I do take siblings but only one set at a time. With one year maternity leaves, the mom needs to leave the older child in care full time ie no loss of income to me to guarantee her the two spaces assuming I know I will have them such as to start over summer when I have one leaving. Also since I only take kids till they start school, by the time mom does the year of mat leave the older child often only has one year left before needing to move on to other care anyways so better to start them at a new home that takes kindergarten kids or mom gives me the baby and puts older child in preschool which then transfers over to the school age program.