At many big hub airports, airlines do provide motorized carts to help passengers, disabled or not, with long distances. (You can flag one downor ask an airline agent to request a pickup.) Most carts run between gates for connecting flights.
During the call, Halvorson tried to reason with Colleen to start CPR, and when she said her boss won't allow that, the dispatcher asked her to hand the phone to someone nearby, or anyone the nurse could flagdown who was not beholden to the facility's policy.