probably the notarized copy of her PR card, a statuory declaration you are her elder brother, notarized copies of her income tax returns, salary slips, ownership documents of her house (if she owns) or rent-deed of the property. These documents should be enough I think.
You would require copy of PR card or Citizenship card or landing form. And you have to prove relation, for that you have to submit birth certificate or marriage certificate of your sister which is evidence of same father.
relationship documents:
1- passport copies of you and your relative in canada (Indian passport has parents names)
2-birth certificates of you and your relative in canada
3-marriage certificates of you and your relative in canada
4-school certificates if they have father/mother names of you and your relative in canada
canadian relative to prove residence
1- PR copy or citizenship documents as applicable
2- canadian tax documents
3-bank statements, credit/debit card transactions
4-job letter(s)
5-any bills in the person's name