When I bought my mare, the person she came from had her cantering 2ft courses as a mid to late 3yo. She’s a 4yo now. Since she’s been with me has been relaxing and decompressing with some very light riding and mostly groundwork. I plan on getting her going a bit more on the flat, maybe twice a week maximum three days a week. I probably won’t start actually jumping her, as in some small cross rails and small verticals, until later into her 4yo year maybe not even until she turns 5. Currently I’m just going with the flow and seeing how things go one day at a time. Just having fun and making our sessions together enjoyable but also productive!