Therefore, extend, we pray you, your merciful glance on those numerous souls who suffer in the fires of Purgatory and free them, that they may be admitted to the beatific vision of God as soon as possible.This certainly suggests that some Catholics believe Mary has the power to free people from Purgatory. Which would possibly mean she can either forgive their sins, or can remove the punishment for their sins.
That may not be "worshipful" to those praying the prayer. And I can't say whether these posts on FR are really correctly "Catholic" or not.
It’s the difference between paranoid rhetoric and free rhetoric. Paranoid rhetoric iin a prayer to Mary requires us to look over our shoulder and make sure that almost every other phrase is “by your intercession”. Free rhetoric delivers us from worrying what those who intend to misunderstand us (by which I emphatically do NOT mean you) will make of what we say.