My boys also have sensory problems. My oldest has Asperger's syndrome, and my youngest has not been diagnosed on the spectrum yet, but I anticipate he will.
School is definitely a place to start,but as another poster mentioned, OT cannot stand alone so it can get tricky. Also, her problems must affect her academic performance in school. I would definitely look into getting some accomodations for her vision issues through the school to start with. Maybe the OT can follow.
As far as private occupational therapists, we have one we absolutely love. His name is Manny Herrera (Manny O.T.& Associates) and he's in Volo (near Fox Lake in NW suburbs). We travel from Highland Park to see him, and he's worth the drive. He's amazing with the kids and has really helped me understand my kids' struggles so I can help them cope. My kids look forward to going every week. He doesn't have a website, but you can google "Manny O.T." and click on the first entry (Health Professionals website) to see his profile/insurance info, etc.
If Volo is just too out of the way, we've also had a good experience with Cawn Krantz & Associates in Northbrook (we only switched because they don't file with insurance and it was too pricey with out of network costs). Have also heard good things about Beth Osten & Associates in Skokie and Therapediatrics in Vernon Hills (they may have other locations as well).
Good luck! If you need to talk/vent, feel free to send me a message.