Sorry for the triple post, but there is probably another element to her texts that I just thought of.
On some level, she knows leaving the same guy three times is a bit... intense. She knows that anyone knowing that fact might judge her for it. So if she can maintain a good relationship with you, and if you appear to still care about her, then she can't be a bad person, right?
So she wants relief from any guilt she feels, and some sort of tangible evidence that her choices aren't incredibly selfish. All the better if the guy she left will still view her as someone he still wants to care for.
