Inheritance is not taxable in Canada, but the interest earned from the inheritance is taxable.
While you were given the legal and beneficial interest in the account in 2002, you had the beneficial interest in it in prior years although verbally. For tax purposes, beneficial interest esp in writing trumps over legal title, meaning you should have reported the interest of pre-2002 years as well.
In the normal course, a taxpayer who has not filed at all would be required to file for 7 years, including the current year, and that a taxpayer who has filed but failed to fully declare, would be required to file for only years that are not otherwise statute barred. Subsection 152(4) generally restricts the CRA from reassessing a return of income for a tax year that is beyond three years from the date of the original Notice of Assessment or of an original notification that no tax was payable for the year. When the normal three-year reassessment period for a tax year ends, the return is considered statute-barred.
However, CRA may use the fact of the disclosure to open, audit and assess statute barred years, under the authority of subparagraph 152(4)(a)(i), which states that the Minister may assess tax, interest or penalties, after the taxpayer's normal reassessment period (3 yrs for most taxpayers) in respect of the year only if the taxpayer :
(i) has made any misrepresentation that is attributable to neglect, carelessness or wilful default or has committed any fraud in filing the return or in supplying any information under this Act.
As a minimum, I would recommend you to amend your last 3 yrs returns to report the interest income, before the CRA catches you and applies the penalties.