These wound separations are not uncommon, though yours is a bit larger than most after a breast reduction. It should be no cause for concern. These wounds invariably heal well. First is seems that some of the tissue may need to be debrided. After this, maybe your surgeon could consider using large sutures to bring the skin together, avoiding excessive tension. If this is not possible, then just allow wound tocontract and grow new skin. It should be 8-10 weeks. Just be patient. I know it is hard now considering your situation but you can shower, put an abx dressing on and go on with life. Avoid heavy lifting as well but this doesn't mean you can't care lovingly for your child.