Hi. I toilet trained children in class. How we start is by bringing them to the toilet every 45 minutes as a start. The time will gradually goes up as the child feel more comfortable. From 45 minutes to 60 minutes to 95 minutes. By then usually the child will know when to inform you. 2.5 years is a good age. Earliest i started with is 20 months.
2.5 yrs seem like a good time. Wish you success.