With kids this young, you need a property that actually segregates toddler programming from older kids—and crucially, gives exhausted parents a break. Grand Velas is purpose-built for your exact ages with its three age-specific zones; Hard Rock's split-wing setup (adults-only Heaven vs. family Hacienda) means you're not corralling little ones through adult dinner crowds. Both are all-inclusive, so no surprise bills when someone melts down at 4 p.m. The Riviera Maya corridor works well for this age range because the resorts understand toddler chaos.