Please make it possible for multiple family members to use a single email address. I run a Kids/Youth Martial Arts Academy & most of my members have their siblings training also. Increasingly now I'm getting parents who trust my service also joining adult classes. It's not appropriate in many cases to expect the parent to monitor multiple email inboxes regarding all their kids messages & communication/app's etc. nor is it appropriate to expect parents to allow their younger kids to have communication within an APP on their private email address & phone (they all need to be supervised by parent mostly). Additionally I have adult members who I want to assign as Trainers & again only 1 email should be required to do both.
Another work around could be to provide a link that connect all the family emails to a 'Master Email' (this could be a check box option with every signup). It would become the default email that all linked accounts copied all communications to.

Additional question would be can a parent monitor their multiple kids accounts including visit pass tracking & messages from coach (with different emails) from a singular Trainerize APP login?