Do you mean Toronto in Canada? Where does the friend live? If they are/were both in Canada, you will have to find someone who knows the applicable laws in Canada and have a chat with that person.
Had these events happened in WA, some of the things you may need to check out may be:
How do you know that the debt had not already been paid? Just because someone still has a promissory note does not necessarily mean that the underlying debt had not already been paid.
You wrote that the note is "to a friend of hers". So, who is the debtor? Was your aunt the lender or the borrower?
How long ago had the debt been due? There may be a statute of limitations on collecting the debt. After a certain time, the lender loses the legal right to make the borrower repay.
Is the borrower still living? In general, creditors may have only a short time to assert claims against a borrower's estate once certain steps have been done in the probate of the borrower's estate.
In short, the answers to your questions may not be as simple as you may want. You may want to review the facts and options with an attorney. Given that there may be a probate proceeding, you may not want to delay in consulting the attorney.
Generally speaking a promissory note obligation is not discharged by the death of lender. The estate would have the right to pursue the remaining balance.
I agree that in WA the person to whom a promissory note is to be paid can enforce the note against the maker's estate. You should speak to a Toronto probate lawyer about relevent time limitations. There is likely one for making claims against an estate as well as a statute of limitations on enforcing a written agreement such as a note. Perhaps the note has been paid; you may want to check on that.