Short answer
Usually yes, family members can be included if they meet the family-member and visa criteria, but they generally cannot be granted before the primary skilled applicant.
Family members need to meet the secondary applicant criteria that apply to them. This can include relationship, health, character and other public interest requirements.
The primary applicant is central to the application. If the primary applicant cannot be granted the visa, family members will usually also have a problem. Some criteria can affect the whole family unit, even where the issue belongs to only one person.