Flight Instructor reported their student had a runway excursion while landing during a solo pattern flight that resulted in the aircraft going into the grass off the runway. No damage or injury was reported.

Narrative

I am the current flight instructor of Person A who is a student pilot working towards his PPL in his Skylane 182T. On Day 0; Person A and I had a training lesson starting at XA00 at ZZZ Airport. We discussed completing the maneuvers required for solo and completing traffic pattern operations. We also discussed wake turbulence avoidance as a review. Person A and I departed ZZZ and completed a variety of maneuvers and a simulated emergency situation. We then proceeded back to ZZZ where we did three full stop landings and one go-around. All three landings were center line; safe; and smooth along with the go-around. I then had him taxi back to the hangar where he dropped me off and I confirmed he felt 100 percent ready to solo. He then completed two solo full stop landings and one go-around as ATC put him on a tight base and he was not stabilized. On the fourth lap; I witnessed him land and exit into the grass off of Runway XX. It appeared he either lost control on the landing or was not on center line. I contacted Tower after the event and they confirmed airport personnel did not find any damage to the airport environment. Person A and I also confirmed there was no damage to the airplane. Tower advised me they would be listing the event as a runway excursion. No injury or damage was reported. Person A and I will be completing more training and landings to help prevent any situation further.