What age should an SPD child start Homeschool/School

I have a daughter turning 5 this year. She has a summer birthday, as in August right before school starts. I personally think she is not ready for school, she is not emotionally ready, and because her SPD has gotten worse and new issues have arisen in the past several months. I do plan on homeschooling her, I have been working with her schooling all along. I had planned on registering her as a homeschooler and starting kindergarten curriculum this year, but have had a change of heart. She is behind in her speech and her SPD has gotten worse, as mentioned above.

I had her in speech for almost 6 months when she decided she no longer wanted to cooperate and at the same time they discharged her from OT after just 4 weeks of therapy. My new plan is that I don't formally register her this year and just concentrate on her therapies and helping her, with school work as an aside. Then, next year when she is 6, and it becomes mandatory, I register her.

I was wondering if anyone had any experiences with age to start school either homeschool or regular school with a child that has SPD or any suggestions or recommendations? The homeschoolers here recommend that I completely wait until she is 6 and just educate through play and whatever else she wants to learn. I don't want to neglect schooling her early enough, but I feel it is important to help her SPD and speech first before we become structured.