Sorry to hear it ended like it did.. It was baby steps and there are always lessons to be learned.
From experience, it might be better to stay away from work. There is plenty of time and opportunities for her to meet another guy.
Maybe this is the time to talk about you being friends with her other partner (or not), and how close you want to be with them (friends or acquaintances), and how soon that should happen. Not set any hard rules, unless you come to that point, more so to start getting different ideas on how comfortable you and she will be when the time does come that she finds her guy.