I got the feeling from her reply to you when she asked who told you, that she was trying to keep her leaving quiet to EVERYONE, not just you. It doesn't seem to me that it was anything personal, but it seems that it was her own issue in that maybe she doesn't do well with goodbye's & she couldn't handle dealing with saying goodbye to everyone & felt for her own well being that it would be better for her to just up & leave without making herself feel horrible with all the goodbyes.

You said she is a colleague T....that means that you are a T & you have people you help who go through similar issues.....what would you tell them? Mindfulness says to look at the big picture, at all the possibilities.....& not to take everything negatively towards one's self when in reality, YOU DON'T KNOW WHY she left without saying anything to you.....your thoughts are your assumptions but they didn't come from what she really felt or her real reasons for leaving the way she did. When we leave our thoughts to our assumptions, we always make them into the worse case that is aimed to hurt us when in reality, it may not have anything to do with that, especially when it sounded like from her reply to you that she was trying to keep her leaving completely quiet & not wanting anyone to tell anyone.

Yes, it hurts.....anytime someone leaves our life that we had a connection to will always hurt.....there is a grieving process that goes on even when they just leave & anger is part of that grieving process & it needs to be handled in that appropriate way so that you can completely process this....but I'm sure that she didn't leave & not say anything just to hurt you or make you feel any less of a person.....it sounds like the way she chose to leave without making any big deal out of it...no going away party. Definitely sounds like someone who can't handle goodbyes IMO