Re:4th Annual Westerly/Misquamicut Beach Trip
For pizza, Vittorio's and Pete's Famous are both very good. Both are Italian style, as opposed to the Greek style usually found here. I've never had pizza at Pizza Plus, but people seem to love it.
The people who run Vittorio's have two other restaurants, one in Westerly and one in Ledyard, CT; the one in Ledyard offers gluten-free pizza, but I don't think either of the Westerly ones do. Call and see. Vesta Bakery on Railroad Avenue makes very good gluten-free cakes (order ahead) and occasionally has something GF available in the case too. Call to check availability and hours.
I've been to Kit Kat's twice and haven't been overly impressed. You may have better luck. If you have a hankering for BBQ as a break from seafood, head down Route 1 to Chester's in Groton.
Speaking of seafood, in case you missed it last time Three Little Fish has moved to Misquamicut, right across from the State beach.
If you head down to Watch Hill, St Clair Annex would be a fun place for the kids. Breakfast and lunch, burgers and stuff, with a popcorn machine outside and an ice cream window. A bit pricey, but good quality. Just a few steps from the carousel and the beach. Mel's in Pawcatuck, just over the bridge, is also good for ice cream.
Finally, on your way to the beach, make a stop at Ritacco's Market or Dunn's Corners Market for great grinders. Also in the Dunn's Corners area, Manfredi's Farm Stand, in addition to produce, has a sort of petting zoo with goats, sheep, a couple donkeys, etc. and vending machines with food for the critters. Kids seem to love it.
Enjoy your vacation, and keep an eye out for Taylor Swift. She recently bought a house in Watch Hill and has been spotted around town occasionally.