Thank you, Xmas, for your stories!
Not surprised at all that they are not a happy couple. My guess is the reason why Jenn still seems to be spoiled by Tim is that he thinks it's easier to give in to her (like with Jackson). Hence the multiple night stay in the hotel for her birthday, etc.
Here's a theory about why they might not be getting Jackson help: they probably don't want to pay for any therapy. It's expensive and if their health insurance isn't top tier, they will have to pay all out of pocket. Of course, people who are "set for life" should be able to prioritize behavioral or occupational therapy for their kid, but we know the Trackers have warped priorities.
If he is special needs he should be going to public school. There he can be evaluated formally and receive services as needed.