Hi Africa, welcome back!

I'm thinking that if you want diversity and Spanish, North Beach may be good for you. Unfortunately, I don't have kids and so am not conversant in school quality issues. But some pockets of North Beach are definitely walkable. The beach is nice, and it's all up-and-coming, going through some major community development. Normandy Isle has a little farmer's market and generally speaking much of North Beach from Normandy Isle to Collins between 70th-80th street has a large S. American presence, mainly from Argentina/Chile. The band shell park in North Beach hosts many cultural events and the North Beach Recreation Center has athletic programs for kids and adults.

As well, North Beach is pretty close to FIU North. Your husband can take Collins Ave up to 163rd street.