2003 Jeep Liberty overheat gauge

My daughters Liberty started overheating a few weeks back so I replaced the radiator (which was clogged) and the water pump because it had a small leak. Everything was fine until yesterday when she was driving it and the gauge suddenly went all the way over to Hot. She immediately parked the car and waitied before driving home. I checked it last night and drove it for 10-15 minutes and no problems...no leaks...and the gauge stayed right in the middle. Now today, she just called me and said it happened again and the only thing the same as yesterday is that it happened on the freeway in both instances. Any advise/suggestions would be greatly appreciated.

Maybe there is air in the system? Use an infra red temp sensor, see if the reading compares with the temp gage, when the vehicle shows hot. I'd definitely want a second opinion for that temp gage.

Feel both the top and bottom radiator hose they should feel about the same. You may have a bad thermostat she would have to drive long enough to get the engine hot.
Does the radiator cap lift if so it is really overheating.
At home put a floor jack under the front with the radiator cap engine running off this should get rid of an air pocket.