I discovered my mom's account was deactivated in March this year. We called Aeroplan and they said to send in residency verification documents via email. Sent in a copy of her passport in along with a recent bill in mid-March and it took them just over three months to respond: "Upon review of your document, we removed the account from our audit and reactivated it.".

We were later able to successfully apply for missing mileage from the period it was deactivated. But still not sure why her account was deactivated. We don't participate in the family plan and she flies very infrequently. Maybe just random draw? The three months wait with no response from Aeroplan in the meantime was very frustrating. I can't imagine how much more of a pain it would be if she actually wanted to use her points during that time.