Parental/caregiver email duplicate allowed

I have many families that I serve and often times there’s only one working or accepted email address for the family. Therefore, when I schedule the children for sessions, the parent/caregiver receives an email for ALL their kids’ sessions coming up. Currently, I’m not sure how I can alert my parents of their children’s upcoming sessions when the parent’s email is not allowed to be added to another profile/child. This is a major concern since I often see siblings at different times or days. Children won’t have an email for me to enter when I create their profile so that is not an option here.