I think you may be right... Could be a seizure.
I don’t think it is a seizure. Seizures usually happen suddenly, and she would not be able to walk out of the ceremony. TIA can happen gradually I saw it happen to my mother in law- she knew a TIA was coming and was able to walk until about 4 minutes later when I had to hold her up. After a TIA , she was exhausted and rested for about 3 days after.