I'm glad SIL had things worked out. And I'm glad that you were the Dad your girls needed.
And you're right about the rest. Nothing you can do about it. Your job now is to be the best Dad you can be to your girls, and to get on with your life with the same integrity you've always had. No one knows where these strange roads will lead one day. The best we can do is live our lives in such a way that we will be at peace with ourselves and the decisions we've made.
You're doing a great thing by your children. There are far worse legacies than that.
Blessings,
Bill
"Don't tell me the sky is the limit when there are footprints on the moon."