Hi, on form IMM 0008 only include the following:
"Family members include a spouse, a common-law partner, dependent children, and dependent child of a dependent child" basis: p.23 of http://www.cic.gc.ca/english/pdf/kits/guides/EG7.pdf.
It is on form IMM 5406 where you have to disclose information on parents, brothers and sisters as well.