As a parent, flying isn't the most relaxing experience. You have to buy tickets, pack, get to the airport, pass through security, and board the airplane.
Fortunately, at least the buying tickets part of the experience may be getting easier. As part of the Federal Aviation Administration (FAA) reauthorization bill, which was signed by President Obama on July 15, 2016, a provision was added in a nod to the difficulties that families encounter. See H.R. 636 (114th Congress) at § 2309.
This provision requires the Secretary of Transportation to examine and, by July 15, 2017, potentially issue a policy directing air carriers to establish a policy requiring a child, under the age of 13, to be seated next to a family member, over the age of 13, to the maximum extent practicable at no additional cost. See bill at § 2309. However, the accompanying member seat cannot be a seat that requires an upgrade to another cabin class or seat with extra legroom for which additional payment is normally required.