Call her on it, but be prepared for her to throw a shit fit. I speak from experience. People who feel entitled to treat others stuff in that way, usually also feel entitled to not get called on their crap.
I once let an ex flatmate use my room for the weekend because I was going to be away and she had friends staying. I asked that she changed the bedding for when I got back and showed her where my spare set was.
On return, not only had she not changed the bedding, which by the way was covered in blood and cum stains, she had put a couple of candles on my tv without a stand and one had melted through the top and the other had dripped down onto the screen. She had broken and ornament and spilled food all over the carpet and used my towel to try and mop it up.
She wasn't there when I got back and didn't turn up for a couple of days but when she did, I went ape shit at her. Rather than apologising and offering to pay for the damage, she had a hysterical meltdown and accused me of deliberately ruining her holiday 
and trying to come between her and her boyfriend. Double .
She was a) a disgustingly dirty cowbag (don't ask me what I found when I had to clear her room after she did a midnight flit without paying rent) and b) utterly, utterly selfish and didn't care one jot about the upset she caused me, not just by the destruction of my stuff but also the breach of trust. If your friend is even a bit like her, be prepared for this to be the end of your friendship which will be a blessing even if it doesn't feel like it at first.