Are they still legally married?
From CIC: www.cic.gc.ca/english/information/applications/guides/5196ETOC.asp#5196E4 (search for "IMM 0008")
Who should be included in your application?
If you are being sponsored as a member of the family class, your spouse or common-law partner must be included in your application as a family member. You must also include all your dependent children from your current and previous relationships, whether they will be going with you to Canada (accompanying family members) or not (non-accompanying family members).
All your family members, whether accompanying you or not, must be declared on your application and be examined. If family members are not examined, it is generally not possible to sponsor them at a later date. This includes children in the custody of a former spouse or common-law partner.
In addition, failure to declare family members on your application and have them examined goes against your duty to provide truthful and accurate information, and may cause you to be found inadmissible to Canada.
