Good Morning @Meg716!
Thank you for posting in the PowerSchool Community. I am sorry to hear you are having difficulty adding your child. To better assist you I would like to clarify a couple of things. First, are you able to log in through the parent portal to see the student's grades, attendance, etc. but just unable to do so on the mobile app? Second, if the first step does not apply to you, is your inquiry related to registering the student?
PowerSchool Community Admin