Who did those miracles God or Mary? Did God NEED Mary to do them? Whos is getting the glory?
Have you ever heard "in Unity there is strength?" Satan is good at doing that--sowing disunity. In fact St. John recounts in his Gospel that Christ told Peter that the Apostles would be "sifted like wheat" but that He (Jesus) had prayed to the Father for him (Peter) to keep his brothers united. Sounds like a serious passage to me.
God glories in His saints. All creation gives glory to God. All, meaning including the demons. It infuriates Satan and his minions to no end that even now, they as part of creation, gives glory to God. They continue to rebel and blaspheme, but they can’t help the fact that they were created by Him.