Answer

Swimmers under 3 years old

NO. This is black and white with no exceptions or grey. Swimmer under the age of 3 years old must be out of the water for at least two hours. Per Kathy Hubbard "Our class structure is designed to keep the number of unders performed safe and productive. There is a science behind the number of unders and that is maximized in one class".

Swimmers over 3 years old

Highly discouraged, but if the parent is insistent book it. Our lessons are a 30 minutes for a reason. Attention spans and energy being two biggies - by class #2 the student isn't as engaged and the integrity of the lesson suffers. It is possible, if the second lesson isn't going well, that we will remove the child from the class to rest.
Action Needed: Back-to-back makeups must be approved by a Site that knows their ability and set as a keyword and noted in tracking.