I honestly don't know how big she is going to get. I knew she was going to be tall but did not expect her to hit that height until at least mid winter. I have done all the training myself with them both and plan to continue to do so. I will be sending them to my trainer tho for 2-3 months in the initial stages of undersaddle work. Mainly as a safety issue for me.
As for riding no. I won't be starting anything under saddle she is at least 3.5-4 years old. She is only a year and a half at the moment.