Hi Livy,
This is my first post too!
I have done the program with my older child when he was 3. The Jones Genius program is a "mastery program." There isn't a set time line or even "grade levels." You work on a skill until the child has it 100 percent down and then you work on the next skill. Every child is different so guessing a time line is difficult. I really like the program and will be using it again with my younger child (now 12 months). Although I have started the Jones Genius Early Reading program with my younger child (in conjunction with the Brill Kids Little Reader), I have not yet started the math portion with her. For myself, I would not set any kind of time line starting out as I think this would put undue pressure on us rather than focusing on skill building and making it fun. If I can offer you any ideas on how to implement or answer any additional questions for you, I would be happy to. In addition, I would recommend that you touch base with either Chris or Dr. Jones to get their thoughts as I can't speak for them. I do know that we would work on reading and math for about 1 hour or more a day at age 3, but my son enjoyed the time and although I can't remember our time line (it was 5 years ago) I thought we were progressing at a rate I was happy with. In addition, we integrated math practice into our everyday life by counting stairs, playing with numbers in the bathtub, etc.
We didn't do writing at the time we started working on the program, we used number stickers I created or did the problems verbally until our handwriting caught up to the math abilities. I know some other people used number stamps. I think I still have time file with the number stickers. If you are interested in them let me know and I can see about attaching them to a post.
Hope this helps. Let me know if I can help with additional info.