I guess it depends on how you want the days to feel. Here are my suggestions for an alternative take on the park.
I always split the park east and west. Take in half of FW and half of WS, and then switch.
You have a very ride heavy FW day and then a walk around the lagoon. I can see why you’ve done that if your Mom, Dad and Sis aren’t coaster people, but on the other hand will they actually want to explore some of the pavilions?
You have some of the street entertainment on the plan but then just the 10 minutes to walk past the pavilions. Is there a chance that actually they might enjoy doing some of the pavilions but allow time to browse? There are gardens (Canada, Japan, UK), museums, shops. If I had to pick say five to explore I might choose Mexico, Japan, Morocco, UK and Canada. If they like shops then France (they have a gorgeous perfume shop) and Germany (Strieff teddies and the caramel shop) and U.K. (tea which is also very interesting inside, you can even do a little tour, and outfitters, plus you can peak through Christopher Robin’s bedroom or even go in and meet Pooh sometime after mid September). And there are Kidcot stations for the little ones. Your sister may even like the Agent P missions in a couple of pavilions.
And if you take my chosen 5 and add America, you could do those with the extended family on day 2. And then your immediate family go and see some of the entertainment in the other pavilions on day 1 which would fit around Via Napoli for dinner.