Travel to Cuba

I’d suggest to get a couple of power banks for your phone since they have a lot of electricity breakages and even at the airport when electricity breaks, there is a risk to get stuck at the customs until electricity works again.
Also try to take with you all medications possible, even the most basic ones like Tylenol and aspirin. They have very bad shortages of many basic goods including medications.
Maybe once you’re at the airport, get couple extra bottles of water. They lose water supply regularly even at resorts so to have a bit of extra water for washing your face and hands will help. Especially with little kids.

Take lots of snacks for the kids! The food isn’t great!
Mosquito nets for pram/ cot
Lots of calpol
Long sleeve swimming suits