Refugees (both Government-Assisted and Privately Sponsored) can apply to sponsor immediate family members under the One Year Window opportunity provision. This program is for refugees who have been in Canada for less than a year. They might sponsor a spouse or common-law partner, dependent children, and children of dependent children, under certain circumstances. Family members identified under this program will be considered as dependants of the principle application.
Under the Sponsorship agreement, the sponsor group is also responsible for the costs of supporting family members who have come to Canada through this program. More information is available from Immigration, Refugees and Citizenship Canada website.