Suppose that she was living at your place and when she breaks up, she leaves bags of her stuff behind.
What do you do?
The best approach is to contact her and give her a deadline: a couple of weeks to a month is usally reasonable.
Say something like:
“You still have a couple of bags at my place – As you can imagine I don’t really want this stuff around… Can you pick them up in the next couple weeks? – I would appreaciate that – Thanks!”
If you don’t hear from her, send her one last reminder and after that either get rid of it or bring it to one of her family members or friends.
You warned her!
It’s her stuff, not yours!
She is the one who should be taking care of it!
If she doesn’t care, neither should you!