Airline power ports vary from AC/110V to DC/15V, with the latter supplying only
up to 75W. In addition, you may need special adapters to be able to use these ports. Your daughter may have had a DC* port providing insufficient juice to power her laptop. In my experience, power port availability has been a crapshoot, and even when one’s there, it’s often barely enough to run off of but it won’t charge a battery (assuming that’s even allowed).
*) You mentioned an AC port, and if that’s correct it must have been switched off. Been there, had that.