Hi
We were in Bali in september with my 2 year old and I was 6 months pregnant. We took some snacks like tiny teddies and dried fruit but didnt really need it. As others have said there is lots of western food available if your kids wont eat anything else. I was careful what I ate just making sure it was super fresh! We stayed in Nusa Dua and none of us got sick.
Have fun!!