As I read this thread I noticed the lack of one ingredient to the mix that is actually very important, in my opinion, and is like yeast to a cake mix.
You changed bullets/loads but didn't have the shooter re-zero thier weapon at the range.
That would be the first place I would look. That leads me to ponder if the shooter, not you, zeroed thier rifle with the original load.
Just food for thought and something to consider. I'm also a fan of "heavy for caliber" loads when shooting, although I have been known to use "light" loads at times. Good luck figuring out what the issue was but I wouldn't worry about it. Just have your daughter keep going to the range and shooting. Nothing replaces trigger time done correctly.