Dear Joyce,
I don't think you will make enough money to support your family by working in Cuba as the national wage is between 10-20 Cuban peso. Most Cubans work for the government and a small percentage work for embassies or foreign firms which might pay better.
There are a small percentage of Cubans who own private business such as restaurants, cafeterias, salons, driving a taxi and lately many mobile phone application business has sprung up in Havana.These Cuban business owners live a rather comfortable live in comparison to the majority. However, foreigners are not allow to own a house or start a business.
Therefore, I would think twice before moving there as life there is not as cheap as most people think.
Best wishes,
Novella