Is there a one-tap way to log in on iPad?

Yes! You can create a one-tap login for your child by using the following steps.

1. Log into the site from Safari on your iPad. 
2. Tap the Share icon at the top of the screen, 
3. Choose Add to Home Screen. (You may need to scroll to the right depending on how many choices you see in the third row of the Share sheet.) Edit the title of the Home screen shortcut if you like. 
4. Tap Add to add this one-tap shortcut to your iPad’s Home screen. (This works for iPhones too.)