I'd count the tomato sauce as a veggie in my household.
If you can ask the mom whether her 3yo eats veggies...what kind?...then I'd bring that. Otherwise, I'd go with the veggie tray for mom and dad, and figure the 3yo won't touch it anyway, so the dip is a moot point. Label the dip so they don't offer her any, but figure it's a grown up snack.
Roasted veggies popped into the oven with the ravioli work, too. Maybe glazed baby carrots?
The best new mom meal ever that I got was a bag of frozen mixed veggies roasted around chicken quarters. It was delicious.