I work in strategy consulting, and the "product" we ultimately deliver is a PP deck. To say I spend 10 hours a day obsessing over minute details (what I believe you call trivial in your post) is not that far out of bounds.
Would be interesting to get some color on why she even needs your slides to begin with? Are her slides and your slides combined into a single document? A few things jump out at me:
My slides are no where near that bad
This suggests quite a lack of confidence in your work product. Are they spectacular, just good enough, or just plain bad?
She changes the colors or does some other non-trivial thing even though my slides look fine
Again, perhaps they are fine, but not that great. Colors, shapes, fonts, alignment, and other "trivial" things make a huge difference on how a PP slide is viewed. It could be that your work is sloppy (e.g "no where near that bad"). It could be that she has OCD. Whatever the reason, she feels you work is not up-to-snuff. Are the edits she makes things that you disagree with? Or, are they generally additive?
Of Friday, she kept asking if I could send her my slides so she could rework them
The final takeaway is that she feels your work is casting a shadow over work product (in the eyes of that same director, who I assume is the "boss"). The compiled document needs to have a consistent look and feel, and if some of it isn't great, the whole document is less impressive.
From an outsiders perspective, given what you've said about this situation, I'd offer a facepunch of sorts. I don't think your PP slides are probably all that great, and her re-work is a triage effort to get them in-line.
My suggestion - stop putting her off, because in doing so, the perception on her end is that you're half-assing it and/or don't care. I would reach out to set up time to go through her edits together. Don't do it once, do it many times. Have her explain why she is making the edits, and what value-add or aesthetic improvements she is able to create by doing so. Over time, perhaps this becomes less of an issue, and you guys can be on one big, happy team together.