I would definitely start with " forgot my password" as long as you know your user name. If you forget the user name as well, then look back in your email to obtain that user name. When you first set up your daughter you would have gotten an email sen...
Did you use the code that was provided to get that deal? If so, I would reach out to customer service. Your actuation date will let them know you joined Public Mobile in the time frame to avail of that deal.