Hi there.
I'm very sorry for your loss.
In short, yes, you can file your mother's 2024 tax return early. However, you will have to follow the CRA's instructions for preparing tax returns for someone who died. See this page for more information: https://www.canada.ca/en/revenue-agency/services/tax/individuals/life-events/doing-taxes-someone-die...
Please note, only the deceased's legal representative can file their final tax return. You can find information about who can be the deceased's legal representative and what is required of that person here: https://www.canada.ca/en/revenue-agency/services/tax/individuals/life-events/doing-taxes-someone-die...
I very much hope that this helps.
