I am very new to the Sensory Integration Disorder (we had our first OT session today), so I am just going to give you my opinion.
My 6 year old SID child was also a 27 week preemie. I would definitely have her screened for early intervention, she should qualify based on her prematurity alone, my son did. With speech and occupational therapy he overcame many of his delays and now mainly has sensory and behavior issues that he may have had regardless of being a preemie. Speech therapy did wonders though, he went from not talking to becoming a super talkative and expressive toddler within a few months. It is amazing what a good therapist can accomplish.
The food issues are an ongoing battle, my 6 year old still has texture issues and is a very finicky eater.
we are in SoCal so we qualified for some services because we had like 2 nurses visiting us for almost 6 months at home monitoring ,her development ,after
I would deffenatley ask her ST all the questions you just asked.