These are hard times. I know it's really bad situation, but from your words you seem good enough to deal with it without creating a mess and this is the best thing to to, for you, for your girl (or ex-girl should I say?), for anybody involved. This is a way to show support, to act as a mature man. At the beginning things are always terrible, you don't know what to do. But time helps a lot. In my case, when I had a similar experience ( I don't know you enough, but everybody has similar events in life, no?) I had to let time pass resisting the temptation to do anything, just to realize later I had a clearer vision on it and I could do more or help myself and the other person to take in in a more positive way. Take the time you need to reflect on this, but don't exaggerate, don't make this event be your obsession.
Good luck!
