Please visit - https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-return/completing-a-tax-return/deductions-credits-expenses/line-30400-amount-eligible-dependant/you-claim-amount-eligible-dependant-line-30400.html - to answer two questions to determine if your late mother qualifies as having eligible dependents that you can claim on her tax return.