It would be best to check your employment contract first to see if any such coverage is mentioned there. If the company does provide a modicum of medical insurance coverage for the family, make sure that it is enough for their needs. You might have to buy an additional medical insurance policy if you have someone with a higher health risk or pre-existing conditions that aren't covered by your employer's policy. 

Employers are encouraged to cover their spouses and dependents, but it is not obligatory under UAE law. So, in the event, they do not cover, it will be your responsibility to arrange for the cover.