I know that she acted mercifully, and from the heart forgave her debtors their debts; do Thou also forgive her debts, whatever she contracted during so many years since the water of salvation. Forgive her, O Lord, forgive her, I beseech You; enter not into judgment with her. Let Your mercy be exalted above Your justice, because Your words are true, and You have promised mercy unto the merciful; which You gave them to be who wilt have mercy on whom You will have mercy, and wilt have compassion on whom You have had compassion. [Confessions IX.13; emphasis added]
Note that he records this not simply as something that he did on the day of her death, nor even only at her funeral, but that he records it as his constant prayer for her, even years after her death, that her sins might be forgiven.
Those who would pretend that St. Augustine is a hero of Protestantism would do well to consider this. He is a hero of the Catholic Faith, and your own hero to the extent that you agree with him (and not vice-versa).