My 5 y.o. daughter was diagnosed in July last year, just after her 5th birthday. These are the things we found successful:
Books: Effective Parenting for the Hard To Manage Child; Growing an In-Sync Child; Sensational Kids: Hope and Help for Children with Sensory Processing Disorder.
Tools: Chewable Necklace (my favorite is by Jellystone Designs) or Chewy Tube (Therapy Express); Hippity Hop; Weighted Vest or Belt; Yoga Motion-Yoga DVD for kids.
Strategies: Spend time outside every day; Make heavy lifting/moving part of the child's daily routine (lifting laundry basket, carrying backpack with 4-5 pounds in it; pushing a box full of toys around; pulling a wagon; Use push ups as a discipline (if you can locate the post regarding this, it's a hoot to read).
Diet: Feingold.org has a diet that, although not easy, has changed my daughter's behavior 90% for the better. Meltdowns are rare--meaning maybe once a week. I discovered the biggest culprit causing bad behavior was BHT. Once we eliminated that, there was a lot of improvement. Then by keeping a diet diary I was able to discover other sensitivities that caused problem behavior.
If I had to pick only one thing from what I've written, I'd say try the Feingold Diet. Membership is $70 a year and worth every penny. They investigate foods for you, you get a nearly 200 page food list to choose from and the support forums are excellent.
Our daughter's SPD symptoms did slowly improve over the past 5 months with OT, but the most dramatic change was in her behavior from the Feingold Diet.
I wish I could say she's 100% potty trained, but at least we've gone from 3-4 accidents a day to 6-8 a week. That improvement also resulted from the diet.
Remember, you are not being too soft. Kids with SPD need accommodations equally as much as people with other disorders. You may wish to keep a diary for a few weeks of your observations of her behavior, which may help you to identify what you would like her OT to work on initially. Welcome to the group!