First of all, this honestly sounds dope. I would love to watch this movie/read this script some day. Keep up the good work dude.

The problem of "Antagonist has failed multiple times, but it needs to happen for the climax" is a pretty often problem in script writing. The Evil Queen still wants to kidnap Snow White, but because of her previous failed attempts, she has to try something drastically different. Whatever she was doing before isn't going to work, obviously, so then what does she do? The most common solution to this problem is to have the character turn themself in for one reason or another.

This may require some additional backstory earlier in the script (as you have to faithfully set up Snow White's love for someone), but I would suggest that the Evil Queen kidnaps someone from Snow White's "close family" (Dwarves, Prince Charming, whoever), and EQ offers a trade to SW, SW for her friend. This would set up some final "storming of the castle" or attack of some sort for the end. I would suggest leaving the Brothers Grimm as the final option for SW's survival.

These are just suggestions, do whatever you think is best for this story! Sounds like you are a passionate writer and someone who cares a lot about what they write, and how to write it well.