"I don't think she seems 'very much empowered' at all, I think that if she was genuinely empowered she would make different choices."
I get what you mean, but at the same time saying "she wouldn't wear that if she was empowered" edges into territory of telling women what they should wear.
Ideally we should all be able to dress however we like without being treated negatively for it or being told we have to dress certain ways to achieve anything. She should be as free to "dress like a stripper" as she is to wear a business suit, or just something casual. Because we are all more than just our clothes.
And I think that's the problem with addressing it at a specific person, it reads like a judgement on her rather than society. Talking in general terms reads less like an attack.
I think it is totally possible to be empowered while dressing in a "sexy" way, because it's about so much more than that. And it does come across as offensive when it is suggested that someone couldn't possibly have picked their own outfit.
Having said all that, the way women are expected to look in the media, is horrific and reduces us to nothing more than mannequins. I just don't see that all women refusing to dress that way will necessarily help matters if it isn't what the women want.
It wasn't actually all that long ago that to "achieve" as a woman you needed to be modest/ladylike, and if you dared dress sexy/slutty you were seen as worthless. I know you weren't saying that she was worthless for dressing that way, but it did read as though you were saying she'd be almost worth more if she dressed more modestly.