Depends how mature they are mentally.
There's lots you can do beforehand that would make the process easier, such as taking her to shows like you are. Making sure she's used to listening to your voice commands like woah, and walk on. Getting her used to having a rug put on and off. Putting things like a folded up rug on her back. Taking her for short walks around the road/trails. Getting her used to dogs, farm machinery etc. If you live near one, taking her to the beach and walking her in hand (and in the water if it's warm enough). Making sure she lunges properly. Getting her used to something touching her belly. Even just reaching over her back and patting her on the other side.
You're lucky you have her early enough that you can do a lot of the ground work with her before getting on her. It makes the actual sitting on her easier, less stressful and less dangerous.
Thanks for all the answers guys!
My youngster will be 3 in June and although her development is great I have decided to put back her back until she is 4 as I don’t want to rush her.
Over the winter I plan to do a little in hand showing and get her used the showing environment!
Aim for around 31/2 maybe 4 but to be fair mine was broken and a 6 year old due to pure lack of development x
The average breaking in age is 3 but before I back a horse I get the vet out to check that all the joints are/ have developed correctly but some racehorses are backed at 2 and other are back at 6 or older
Hope this helps
It depends on the development of the horse. However, I usually aim for 3. At three, it would be very basic backing and mouthing. Enough that the horse doesn't panic, and can walk, trot, canter and more importantly, stop. After that, they're turned out to finish developing until they're 4 when they're brought it to start their schooling.
In saying that, if a 3 year old is particularly scrawny or weak, they get left until they're older.