Ok ... if you cancelled the auto renew and the CC info is no longer in the system (cards really should be cancelled/closed and if mom was on the account then a new account in her name only should be established) then you can ignore the junk emails that are sent. Call them spam and they will go away naturally.
You cannot cancel or close the TT account itself ... instead it will go dormant naturally.
See this TurboTax support FAQ for updating or confirming the information in your Advantage account - https://ttlc.intuit.com/questions/1900547-how-do-i-update-or-confirm-the-info-in-my-turbotax-advanta...
If you no longer want the Advantage subscription see this TurboTax support FAQ for cancelling the subscription - https://ttlc.intuit.com/questions/1901052-how-do-i-cancel-my-turbotax-advantage-subscription
